Right click (map move) + scale/rotate commands should not interfere with each other

[taylor.smock]

Steps to reproduce:

1. Download data
2. Select an object (I used a building)
3. Enter either scale or rotate mode
4. Right click and release or attempt to move map
5. Move mouse pointer

EDIT: It looks like this is from a workaround for #2483.
EDIT2: It looks like there is different buggy behavior under Windows and Linux. If the workaround for #2483 is removed, it is likely that Mac will have the same buggy behavior.

[taylor.smock]

In 18767/josm:

Fix #23015, see #2483: Right click (map move) + scale/rotate modes should not interfere with each other

The workaround added for #2483 (r1634, Java 5) does not appear to be needed
anymore (tested with a Magic Mouse in one-button mode under Java 8). Removing
the workaround fixes the behavior whereby a right-click will cause the
scale/rotate mode to be enabled.

To fix extraneous commands being generated during a map pan when scale/rotate
mode is enabled, we check to see if the right mouse button is down in
updateCommandWhileDragging.