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

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

jupyter_server/serverapp.py

@@ -459,7 +459,7 @@ def init_settings(
             "allow_password_change": jupyter_app.allow_password_change,
             "server_root_dir": root_dir,
             "jinja2_env": env,
-            "serverapp": jupyter_app
+            "serverapp": jupyter_app,
         }
 
         # allow custom overrides for the tornado web app.