Configure devstack solum to listen on 0.0.0.0

This is because devstack registers the endpoints based on the host_ip set
in localrc and we also use 127.0.0.1 for the trigger test.

Change-Id: Ia940ee455416690680a094eebae0c355e2904593
Merge "Configure devstack solum to listen on 0.0.0.0"