Make octavia reproducible
Make octavia reproducible

This is a forward of the patch attached to the Debian bug here:
https://bugs.debian.org/908222

Whilst working on the Reproducible Builds effort [0], we noticed
that octavia could not be built reproducibly.

This is because it embeds the hostname in the config file (which
also gets picked up in the documentation and the documentation
index files.)

 [0] https://reproducible-builds.org/

Change-Id: Ic290d733b2cd927f05a2becef3b3d9984d1b7a73

openstack/octavia,openstack/octavia,openstack/octavia