ImageryCache plugin wasn't properly deprecated

[rickmastfan67]

In [8772], the 'ImageryCache' plugin was deprecated. However, it seems that 'PluginHandler' is case sensitive, meaning that you can still download/activate the plugin in r8772. (As seen in my status report below.)

So, that file needs to be updated with the case sensitive version of the name.

imagerycache ---> ImageryCache

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2015-09-21 01:33:29
Last Changed Author: Don-vip
Revision: 8772
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Relative URL: ^/trunk
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2015-09-21 02:21:30 +0200 (Mon, 21 Sep 2015)
Last Changed Rev: 8772

Identification: JOSM/1.5 (8772 en) Windows 7 64-Bit
Memory Usage: 361 MB / 1820 MB (180 MB allocated, but free)
Java version: 1.7.0_79, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM

Plugins:
- ImageryCache (31552)
- OpeningHoursEditor (31241)
- buildings_tools (31558)
- measurement (31289)
- osmarender (31241)
- reverter (31241)
- turnrestrictions (31562)
- undelete (31241)
- utilsplugin2 (31463)

[Don-vip]

In 8773/josm:

fix #11882 - ImageryCache plugin wasn't properly deprecated