Fix approving a new package request in the docker namespace
    
    When we approve a new package request, in any namespace, we normally go
    then through all the other pending requests to automatically create the
    branch (for the branches for which we can).
    With non-rpm namespaces, this logic was broken since we were not including
    the namespace in the search for other requests and we were ending up
    with an exception saying that there are no such package.
    This was confusing when processing the requests via pkgdb-admin since it
    would return an error (not even a clear one) and then when checking the
    UI, the new package was created.
    
    This commit fixes that situation.