Allow non-use of cfg.CONF in securemessage

If someone passes a ConfigOpts instance other than cfg.CONF, we need
to register the group and options with it.

Change-Id: I10908d5e29d8a871ae29a5d3fa3f415e487f23b8
Don't attempt to patch eventlet without the patch

Some projects, like horizon, do not carry the eventlet patch.

Change-Id: I24ffad9ab7852be44e5d6c8805aa0a47647e21cc
Merge "Allow non-use of cfg.CONF in securemessage"