There has been one confirmed denial-of-service against the opendev
git servers due to an openstack-ansible deployment failing to
correctly use cached wheels from the repo server and instead clone
and build the source code for each openstack service on each target
host.
Whilst we wait for further information to understand the root cause
of that DOS, it is possible to adjust the user-agent that git uses
on a per-domain basis.
This patch sets the user-agent to a string which identifies that
OSA is responsible for git operations, which version of OSA is
in use, and if the host is a deploy host or an AIO build.
Change-Id: I8157c744a58a8ade56776e8cb29956a8abed081c
672b720b59