Backport "HBASE-29631 Fix race condition in IncrementalTableBackupClient when H…" to branch-2.6#7359

rmdmattingly merged 1 commit intobranch-2.6apache/hbase:branch-2.6from

HBASE-29631-branch-2.6apache/hbase:HBASE-29631-branch-2.6Copy head branch name to clipboard