Fixes bug with keypair creating
Fixes bug with keypair creating

If try create several shares with share-network that does not have
service vm yet, all threads tries create it, and after race condition
only first successful, other fails.

Closes-bug: 1292704
Change-Id: I10ae1200803201bd621f806a1fe88ffb9ba1399e

openstack/manila,scality/manila,sajuptpm/manila,NetApp/manila,openstack/manila,redhat-openstack/manila,jcsp/manila,weiting-chen/manila,bswartz/manila,weiting-chen/manila,jcsp/manila,vponomaryov/manila,sajuptpm/manila,bswartz/manila,NetApp/manila,scality/manila,redhat-openstack/manila,vponomaryov/manila