ISPN-3329 DatabaseStoredIndexTest.indexWasStored random failures

 - https://issues.jboss.org/browse/ISPN-3329

I believe the issue was fixed by @gustavonalle in 74db418

I just had to add an equals implementation to the recently created FileListCacheValue (this should have been done when I introduced the new type but didn't notice as this test was disabled)