loop bug fix

src/components/ConcernementMapItem.vue

@@ -916,6 +916,7 @@ export default {
           this.paper_main_object.children[child_name].remove();
         }
       });
+      this.paperContentsIsSet = false;
     },
     addNewPaperSymbolInstance(name, back, scale){
       let instance = new paper.SymbolItem(this.paper_symbol_definitions[name]); // , {x:0,y:0}