[git_cl] Fix missing variable

Bug: b/351071334
Change-Id: I337dc37c69be6eb2197bda23098506eb1ab90709
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5709132
Reviewed-by: Yiwei Zhang <yiwzhang@google.com>
Commit-Queue: Allen Li <ayatane@chromium.org>

git_cl.py

@@ -3730,12 +3730,12 @@ class GitAuthConfigChanger(object):
         return cls(
             cwd=os.getcwd(),
             host_shortname=host_shortname,
-            mode=cls._infer_mode(),
+            mode=cls._infer_mode(gerrit_host),
             remote_url=remote_url,
         )
 
     @staticmethod
-    def _infer_mode() -> GitConfigMode:
+    def _infer_mode(gerrit_host: str) -> GitConfigMode:
         """Infer default mode to use."""
         if not newauth.Enabled():
             return GitConfigMode.OLD_AUTH