Add retries for keystone-manage db_sync and make relationships more strong.

This retries need for prevent broke deploy, if puppet make decision to restart
haproxy near this exec.

Closes-bug: #1319087
Change-Id: I0e61d2bdf04a11c936ca0bc7b932478fa28f360e
Merge "Add retries for keystone-manage db_sync and make relationships more strong." into stable/4.1