Issue: It is possible that the keyspace dir be empty without .db files, in this case the cassa-db-restore.sh fails to copy .db from empty dir and aborts and remaning keyspaces are not restored.
Issue:
It is possible that the keyspace dir be empty without .db files,
in this case the cassa-db-restore.sh fails to copy .db from empty
dir and aborts and remaning keyspaces are not restored.

Fix:
Do copy/restore only if there are .db files precent in a table
directory of a keyspace.

Change-Id: I592560cfa7812ca70ba7ebca4408c8f2033c6278
Closes-Bug: 1625815

tcpcloud/contrail-controller,tcpcloud/contrail-controller,tcpcloud/contrail-controller,tcpcloud/contrail-controller,tcpcloud/contrail-controller,tcpcloud/contrail-controller