[t]rack bindkey applied to digital graphs if they are selected, although track does not work if pointing in digital graphs

src/callback.c

@@ -488,7 +488,7 @@ static int waves_callback(int event, int mx, int my, KeySym key, int button, int
         }
       }
       else if((key == 't') ) {
-        if(!gr->digital) {
+        if(track_dset != -2) {
           if(i == xctx->graph_master || r->sel) {
             my_strdup(1448, &r->prop_ptr, subst_token(r->prop_ptr, "dataset", my_itoa(track_dset)));
           }