IntegrationTest.testConcurrentETagChanges always fails

The test always fails since the ISPN-5857 fix was integrated.

When executing a PUT operation, the REST server always looks up the previous value, and if it exists, it executes a cache.replace(k, old, new) cache operation instead of a regular push. But the cache is configured with value-equivalence=AnyEquivalence, so the replace fails if the REST server is not the primary owner.

It was successful before the ISPN-5857 fix only because the server was the primary owner of the key, and then only because ValueMatcher.equal() checks identity first.