It seems that at times of high concurrency, libvirt
occassionally fails on supposedly some race condition
what leads to client failure (e.g. Ironic). This change
is to tell Ironic that it should try some more times rather
than bailing out right away.
Change-Id: I5848d721305c887fb7803ca4b302565aa4b83c88
Story: #2001798
Task: #15076