Fix bug breaking local builds.
This bug was reported by @nphilipp here https://bodhi.fedoraproject.org/updates/FEDORA-2018-c9c3a37d96
The issue is that the `record_filtered_rpms` method returns a new xmd
buildrequires block, but whole buildrequires entries were omitted in the return
value for local builds. This one-liner includes them again.