ConcurrentModificationException in PreferencesWriter.write during restart

[Mongenet]

What steps will reproduce the problem?

1. start JOSM
2. bug happen during startup

What is the expected result?

What happens instead?

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

URL:http://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2016-06-04 17:28:58 +0200 (Sat, 04 Jun 2016)
Build-Date:2016-06-04 15:31:27
Revision:10327
Relative:URL: ^/trunk

Identification: JOSM/1.5 (10327 fr) Linux Arch Linux
Memory Usage: 400 MB / 7111 MB (328 MB allocated, but free)
Java version: 1.8.0_92-b14, Oracle Corporation, OpenJDK 64-Bit Server VM


Last errors/warnings:
- E: java.util.ConcurrentModificationException
- W: java.io.IOException: Cannot run program "lsb_release": error=2, Aucun fichier ou dossier de ce type. Cause : java.io.IOException: error=2, Aucun fichier ou dossier de ce type

java.util.ConcurrentModificationException
	at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1211)
	at java.util.TreeMap$EntryIterator.next(TreeMap.java:1247)
	at java.util.TreeMap$EntryIterator.next(TreeMap.java:1242)
	at org.openstreetmap.josm.data.preferences.PreferencesWriter.write(PreferencesWriter.java:47)
	at org.openstreetmap.josm.data.Preferences.save(Preferences.java:537)
	at org.openstreetmap.josm.data.Preferences.saveDefaults(Preferences.java:515)
	at org.openstreetmap.josm.Main.exitJosm(Main.java:1127)
	at org.openstreetmap.josm.actions.RestartAction.restartJOSM(RestartAction.java:85)
	at org.openstreetmap.josm.actions.RestartAction.actionPerformed(RestartAction.java:65)
	at org.openstreetmap.josm.gui.MainApplication$7.run(MainApplication.java:611)
	at java.lang.Thread.run(Thread.java:745)

[Don-vip]

In 10379/josm:

see #12963 - ignore warning on Linux systems which do not provide lsb_release

[Don-vip]

In 10380/josm:

fix #12963 - ConcurrentModificationException in PreferencesWriter.write during restart