Resolve oauth dependency after paste pipeline is loaded

When trying to authenticate with the oauth plugin, it is
possible that the dependency is not yet loaded, and as a result
the user will receive an error message: "Oauth is disabled"

This patch will ensure the dependency is loaded after the pipeline

Fixes: bug #1264803

Change-Id: I37484bf844896b1a1b560923a8afaf99e91635e4
Merge "Resolve oauth dependency after paste pipeline is loaded"