[bug] fix new group being created when editing a link

Author: zombieFox

src/js/link.js

@@ -1083,6 +1083,8 @@ var link = (function(){
 stagedLink.link=JSON.parse(JSON.stringify(arrayItem));
 stagedLink.position.origin.item=index;
 stagedLink.position.destination.item=index;
+stagedLink.position.group.new=null;
+stagedLink.position.group.name=null;
 group.querySelector(".group-body").appendChild(render.item.link());
 });
 }else{