webhooks: Remove unused imports.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

zerver/webhooks/trello/view/__init__.py

@@ -1,10 +1,9 @@
 # Webhooks for external integrations.
 import ujson
 from typing import Mapping, Any, Tuple, Optional
-from django.utils.translation import ugettext as _
 from django.http import HttpRequest, HttpResponse
 from zerver.decorator import api_key_only_webhook_view, return_success_on_head_request
-from zerver.lib.response import json_success, json_error
+from zerver.lib.response import json_success
 from zerver.lib.request import REQ, has_request_variables
 from zerver.lib.webhooks.common import check_send_webhook_message, \
     UnexpectedWebhookEventType

zerver/webhooks/trello/view/board_actions.py

@@ -1,4 +1,4 @@
-from typing import Any, Dict, Mapping, MutableMapping, Optional, Tuple
+from typing import Any, Dict, Mapping, Optional, Tuple
 
 from .exceptions import UnknownUpdateBoardAction
 

zerver/webhooks/trello/view/card_actions.py

@@ -1,5 +1,4 @@
-from datetime import datetime
-from typing import Any, Dict, Mapping, MutableMapping, Optional, Tuple
+from typing import Any, Dict, Mapping, Optional, Tuple
 
 from .exceptions import UnknownUpdateCardAction