fixed coverity warning message (ua_list_removeLast, null pointer derefencing)

src/util/ua_list.c

@@ -119,7 +119,6 @@ UA_Int32 UA_list_removeLast(UA_list_List* list, UA_list_PayloadVisitor visitor){
 		list->size--;
 		if(list->size == 1){
 			list->first = temp;
-			list->first->next = UA_NULL;
 		}else if(list->size==0){
 			list->first = UA_NULL;
 		}