Misleading error message during failed import from 3rd-party servers

[StefanB]

What steps will reproduce the problem?

1. Try to import from a non-functioning web server using josm remote control, eg
2. ​http://127.0.0.1:8111/import?url=http%3A%2F%2Fraba.openstreetmap.si%2FRabaSplits_20151031_EPSG4326%2Fraba1207dissJosm.zip
3. wait for the import to fail

What is the expected result?

Error message saying that there was a problem with target server (eg raba.openstreetmap.si in above case)

What happens instead?

Misleading error message is shown:
"Failed to upload data to or download data from '​https://api.openstreetmap.org/api/0.6/' due to a problem with transferring data. Details (untranslated): Read timed out"
Note that the mentioned URL is wrong, misleading!

Please provide any additional information below. Attach a screenshot if possible.

Stacktrace in console:
INFO: RemoteControl received: GET /import?url=http%3A%2F%2Fraba.openstreetmap.si%2FRabaSplits_20151031_EPSG4326%2Fraba1207dissJosm.zip HTTP/1.1
INFO: GET ​http://raba.openstreetmap.si/RabaSplits_20151031_EPSG4326/raba1207dissJosm.zip
ERROR: org.openstreetmap.josm.io.OsmTransferException: java.net.SocketTimeoutException: Read timed out. Cause: java.net.SocketTimeoutException: Read timed out
org.openstreetmap.josm.io.OsmTransferException: java.net.SocketTimeoutException: Read timed out

at org.openstreetmap.josm.io.OsmServerReader.getInputStreamRaw(OsmServerReader.java:205)
at org.openstreetmap.josm.io.OsmServerReader.getInputStreamRaw(OsmServerReader.java:104)
at org.openstreetmap.josm.io.OsmServerReader.getInputStreamRaw(OsmServerReader.java:91)
at org.openstreetmap.josm.plugins.opendata.core.io.NetworkReader.parseOsm(NetworkReader.java:132)
at org.openstreetmap.josm.actions.downloadtasks.DownloadOsmTask$DownloadTask.parseDataSet(DownloadOsmTask.java:324)
at org.openstreetmap.josm.actions.downloadtasks.DownloadOsmTask$DownloadTask.realRun(DownloadOsmTask.java:332)
at org.openstreetmap.josm.gui.PleaseWaitRunnable.doRealRun(PleaseWaitRunnable.java:93)
at org.openstreetmap.josm.gui.PleaseWaitRunnable.run(PleaseWaitRunnable.java:161)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

Caused by: java.net.SocketTimeoutException: Read timed out

at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:170)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:246)
at java.io.BufferedInputStream.read1(BufferedInputStream.java:286)
at java.io.BufferedInputStream.read(BufferedInputStream.java:345)
at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:704)
at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:647)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1536)
at sun.net.www.protocol.http.HttpURLConnection.access$200(HttpURLConnection.java:90)
at sun.net.www.protocol.http.HttpURLConnection$9.run(HttpURLConnection.java:1433)
at sun.net.www.protocol.http.HttpURLConnection$9.run(HttpURLConnection.java:1431)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessController.doPrivilegedWithCombiner(AccessController.java:782)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1430)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
at org.openstreetmap.josm.io.OsmServerReader.getInputStreamRaw(OsmServerReader.java:170)
... 12 more

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2015-11-24 00:04:12 +0100 (Tue, 24 Nov 2015)
Build-Date:2015-11-23 23:14:21
Revision:9060
Relative:URL: ^/trunk

Identification: JOSM/1.5 (9060 en) Mac OS X 10.11.1
Memory Usage: 583 MB / 3641 MB (402 MB allocated, but free)
Java version: 1.8.0_66, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
VM arguments: [-Djava.security.policy=file:/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/lib/security/javaws.policy, -DtrustProxy=true, -Djnlpx.home=<java.home>/bin, -Djava.security.manager, -Djnlpx.origFilenameArg=/Users/stefanb/Library/Application Support/Oracle/Java/Deployment/cache/6.0/56/1ee8cfb8-24994f11, -Djnlpx.remove=false, -Dsun.awt.warmup=true, -Djava.util.Arrays.useLegacyMergeSort=true, -Dmacosx.jnlpx.dock.name=JOSM, -Dmacosx.jnlpx.dock.icon=/Users/stefanb/Library/Application Support/Oracle/Java/Deployment/cache/6.0/16/47ee53d0-2fbc6aa0.icns, -Djnlp.application.href=https://josm.openstreetmap.de/download/josm.jnlp , -Djnlpx.jvm="/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/bin/java", -Djnlpx.vmargs=LURqYXZhLnV0aWwuQXJyYXlzLnVzZUxlZ2FjeU1lcmdlU29ydD10cnVlAC1Eam5scC5hcHBsaWNhdGlvbi5ocmVmPWh0dHBzOi8vam9zbS5vcGVuc3RyZWV0bWFwLmRlL2Rvd25sb2FkL2pvc20uam5scCAA]

Plugins:
- apache-commons (31772)
- ejml (31772)
- geotools (31774)
- jts (31772)
- opendata (31772)
- utilsplugin2 (31772)

Last errors/warnings:
- E: org.openstreetmap.josm.io.OsmTransferException: java.net.SocketTimeoutException: Read timed out. Cause: java.net.SocketTimeoutException: Read timed out