Fixes a broken flake8 test (payload_api.py)

app/api/v2/handlers/payload_api.py

@@ -83,7 +83,7 @@ async def post_payloads(self, request: web.Request):
         tags=['payloads'],
         summary='Delete a payload',
         description='Deletes a given payload.',
-        responses = {
+        responses={
             204: {"description": "Payload has been properly deleted."},
             404: {"description": "Payload not found."},
         })