gf-complete: update submodule to newest upstream

Keep the tree cleaner!

Signed-off-by: Greg Farnum <gfarnum@redhat.com>
Merge pull request #3129 from ceph/wip-gfcomplete-dirty

gf-complete: update submodule to newest upstream

Reviewed-by: Loic Dachary <ldachary@redhat.com>