TimestampsRegionCache cache clear throwing an NPE

[EzequielB]

When calling the clear method an NPE is thrown:

Tests run: 2, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.18 sec <<< FAILURE! - in com.hazelcast.hibernate.local.TimestampsRegionCacheTest
clearCache(com.hazelcast.hibernate.local.TimestampsRegionCacheTest)  Time elapsed: 0.026 sec  <<< ERROR!
java.lang.NullPointerException: null
	at com.hazelcast.hibernate.local.TimestampsRegionCache.createMessage(TimestampsRegionCache.java:71)
	at com.hazelcast.hibernate.local.LocalRegionCache.maybeNotifyTopic(LocalRegionCache.java:195)
	at com.hazelcast.hibernate.local.LocalRegionCache.clear(LocalRegionCache.java:278)
	at com.hazelcast.hibernate.local.TimestampsRegionCacheTest.clearCache(TimestampsRegionCacheTest.java:87)