Fixed resource change listener for repo editor

Problem before was that the repo metadata editor did not close if its
corresponding file gets deleted or moved away from its repodata folder.
I think it should be strict in enforcing that the repomd.xml file be
inside repodata folder just like how createrepo structures its
directory.

The createrepo project only know to find repomd.xml within repodata
folder and no where else. It isn't technically supposed to be edited
anyways but needed to link the form editor to a resource to allow the
use of createrepo.

Signed-off-by: Neil Guzman <nguzman@redhat.com>