Disable ehcache update check on startup

On startup ehcache does a network access to check for updates:

INFO  [net.sf.ehcache.CacheManager@797e7185] [net.sf.ehcache.util.UpdateChecker] New update(s) found: 2.6.5 [http://www.terracotta.org/confluence/display/release/Release+Notes+Ehcache+Core+2.6]. Please check http://ehcache.org for the latest version.

It's not the job of the code to do such checks at runtime (including potentially slow network access).

This can be disabled by setting the system property net.sf.ehcache.skipUpdateCheck=true