Add missing parameter in prepare_service for api
Add missing parameter in prepare_service for api

Although the bug #1526888 (prepare_service() - duplicate function) got merged
https://review.openstack.org/#/c/258007/ we didn't see that the file in
(watcher/cmd/api.py) api didn't have sys.argv parameter.

Change-Id: I458b4ff169684131a20ef6ac090b1c918f08d427
Closes-Bug: 1526888

stackforge/watcher,openstack/watcher,openstack/watcher,stackforge/watcher