Use Popup.back() instead of Popup.close() to get no conflicts if a Popup is opened as "Sub Popup"

- .back() is also .close() if there is no "popup layer" left

client/components/cards/minicard.js

@@ -106,7 +106,7 @@ BlazeComponent.extendComponent({
           if (!Number.isNaN(sort)) {
             let card = this.data();
             card.move(card.boardId, card.swimlaneId, card.listId, sort);
-            Popup.close();
+            Popup.back();
           }
         },
       }