Always pass the conf.obs_api parameter

so that osc does not ask about a login to api.opensuse.org.
In IBS Jenkins there is no need to contact OBS.
Merge pull request #22 from mvidner/explicit-api-parameter

Always pass the conf.obs_api parameter
Merge remote-tracking branch 'origin/master' into maintenance_mode

Conflicts:
	VERSION
	package/rubygem-packaging_rake_tasks.changes