fix bug in script

CrossWOZ.py

@@ -292,7 +292,7 @@ class CrossWOZ(datasets.GeneratorBasedBuilder):
                     "goal": convert_goal(dialog["goal"]),
                     "task description": dialog["task description"],
                     "type": dialog["type"],
-                    "messages": messages
+                    "messages": messages,
                     "final_goal": convert_goal(dialog["final_goal"])
                 }
                 key += 1