don't check the real usercount when drawing masks, this way fake user masks can be edited in the dope sheet. (was cause of masks mysteriously not showing in the dope sheet, making masks fake user by default made this more common an issue)

source/blender/editors/animation/anim_filter.c

@@ -1418,9 +1418,9 @@ static size_t animdata_filter_mask(ListBase *anim_data, void *UNUSED(data), int
 		size_t tmp_items = 0;
 		
 		/* only show if mask is used by something... */
-		if (ID_REAL_USERS(mask) < 1)
+		if (mask->id.us < 1)
 			continue;
-		
+
 		/* add mask animation channels */
 		BEGIN_ANIMFILTER_SUBCHANNELS(EXPANDED_MASK(mask))
 		{