Flaky Cassandra test: testEdgeTTLTiming

[FlorianHockmann]

[ERROR] Failures: 
[ERROR]   ThriftGraphCacheTest>JanusGraphTest.testEdgeTTLTiming:5175 expected: <false> but was: <true>

Job was:

MODULE='cassandra' ARGS='-Dtest=**/graphdb/thrift/* -Dtest.skip.unordered=true -Dtest.skip.ssl=true -Dtest.skip.serial=true'

[FlorianHockmann]

Also a problem for CQL:

Error:  Failures: 
Error:    CQLGraphCacheTest>JanusGraphTest.testEdgeTTLTiming:6528 expected: <false> but was: <true>
[INFO] 
Error:  Tests run: 407, Failures: 1, Errors: 0, Skipped: 2

job was:

tests (cql, -Pcassandra3-murmur -Dtest="**/graphdb/cql/*", murmur-graphdb, -Pjava-11, 11) 

in PR #3117.

[FlorianHockmann]

Also flaky for CQL without Cache:

Error:  org.janusgraph.graphdb.cql.CQLGraphTest.testEdgeTTLTiming  Time elapsed: 3.471 s  <<< FAILURE!
org.opentest4j.AssertionFailedError: expected: <false> but was: <true>