autofix simple cases of old style wikipedia tags

[mkoniecz]

What steps will reproduce the problem?

1. create node
2. add wikipedia:de=Mielesdorf tag
3. run validator

What is the expected result?

Validator makes autofix available that would remove wikipedia:de=Mielesdorf tag and add wikipedia=de:Mielesdorf tag

What happens instead?

"wikipedia tag is not set, but a '​wikipedia:de' tag is. Make sure to use wikipedia=language:value together with wikidata tag. (1)" warning not offering automated change

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

This automatic rule should not run in cases where wikipedia tag is already present. In cases of multiple old style Wikipedia tags and no wikipedia tag it either may select any or refuse to run.

real case of that problem (fixed by my manual edit): ​https://www.openstreetmap.org/node/1502918091

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2019-02-23 17:46:51 +0100 (Sat, 23 Feb 2019)
Build-Date:2019-02-24 02:30:49
Revision:14802
Relative:URL: ^/trunk

Identification: JOSM/1.5 (14802 en) Linux Ubuntu 16.04.5 LTS
Memory Usage: 714 MB / 869 MB (158 MB allocated, but free)
Java version: 1.8.0_201-b09, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Screen: :0.0 1920x1080
Maximum Screen Size: 1920x1080
Dataset consistency test: No problems found

Plugins:
+ OpeningHoursEditor (34867)
+ buildings_tools (34867)
+ continuosDownload (82)
+ imagery_offset_db (34867)
+ measurement (34867)
+ reverter (34867)
+ todo (30306)

Last errors/warnings:
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out
- W: java.net.SocketTimeoutException: Read timed out

[mkoniecz]

Old style wikipedia tags may be desirable in some regions (Ukraine, Belarus) as workaround for political and cultural issues.

Elsewhere old-style wikipedia tags are fairly rare.