Add new check for empty directories to innobackupex-runner

The /usr/local/bin/innobackupex-runner.sh script on the dbs node
won't run correctly if an empty directory has been left from
a previous run. We need to add additional condition for them.

Closes-Bug: PROD-35625
Change-Id: I558a7465431a096657f4c9d6c7f89eb700d6eae8
1 file changed