bugfix : don't update group values if group deleted

SequenceMgr.js

@@ -417,6 +417,7 @@ function struct_buildValuesFromSeq(){
 			if(groupCue.name==undefined){
 				script.log("cue " + groupList[i] + "not found, removing group (keys survive this)");
 				groups.removeContainer(groupList[i]);
+				break;
 			}
 
 			//else check at key level