Make sure we only have one sstable when running offline relevel first time
Make sure we only have one sstable when running offline relevel first time

Patch by marcuse; reviewed by Jason Brown for CASSANDRA-14602

blerer/cassandra-dtest,stef1927/cassandra-dtest,pauloricardomg/cassandra-dtest,stef1927/cassandra-dtest,blerer/cassandra-dtest,bdeggleston/cassandra-dtest,iamaleksey/cassandra-dtest,aweisberg/cassandra-dtest,pauloricardomg/cassandra-dtest,bdeggleston/cassandra-dtest,aweisberg/cassandra-dtest,iamaleksey/cassandra-dtest,pcmanus/cassandra-dtest