Let's make sure when we drop a reference to a unit, that we run the GC queue on
it again.
This (together with the previous commit) should deal with the GC issues pointed
out in:
https://github.com/systemd/systemd/pull/2993#issuecomment-
215331189
if (!ref->unit)
return;
+ /* We are about to drop a reference to the unit, make sure the garbage collection has a look at it as it might
+ * be unreferenced now. */
+ unit_add_to_gc_queue(ref->unit);
+
LIST_REMOVE(refs, ref->unit->refs, ref);
ref->unit = NULL;
}