Fallback to creds provider for fixed IP network if no network_for_ssh

When using fixed IPs for ssh and dynamic credentials and
network tenant isolation, if network_for_ssh is not set
attempt to just lookup the proper address to use from the
server using the network resource that's stashed in the
credentials provider.

Change-Id: I045bdf6a8e3b22293a3c804538aed7c75cb36180
Closes-Bug: #1611100
1 file changed