How to clean geo-replication leftovers if volumes were deleted while session was set?

Issue

If volumes which had geo-replication set up were deleted but geo-replication was not deleted, there will be a lot of errors dropped into:

/var/log/glusterfs/geo-replication-stale/mbr

[2019-07-03 15:52:36.449695] E [resource(slave):1416:handle_mounter] MountbrokerMounter: glusterd answered  mnt=
[2019-07-03 15:52:36.450097] E [syncdutils(slave):817:errlog] Popen: command returned error cmd=/usr/sbin/gluster --remote-host=localhost --log-file=- system:: mount georep user-map-root=georep aux-gfid-mount acl log-file=/var/log/glusterfs/geo-replication-slaves/097a7bc4-80a9-4040-b0f5-95b04717eee2:10.186.229.159.%2Fvar%2Flib%2Fheketi%2Fmounts%2Fvg_9107afdcff2d7c19654b02efa9f07e89%2Fbrick_df3d53338f328172b8c92f4ddcc69fa6%2Fbrick.vol_91d1a4fecc0e5f2497cafad3c34ef8c5.gluster.log volfile-server=localhost volfile-id=vol_91d1a4fecc0e5f2497cafad3c34ef8c5 client-pid=-1   error=1