[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

jupyter_server_proxy/config.py

@@ -267,7 +267,7 @@ def cats_only(response, path):
         is given and progressive is None, the proxying will never be progressive. If progressive is a function,
         rewrite_response will only be called on requests where it returns False. Progressive takes precedence over
         rewrite_response when both are given!
-    """
+    """,
     ).tag(config=True)
 
     update_last_activity = Bool(