[git_cl] Fix comment about GetCodereviewServer

Previous comment was... lacking.  Actually, wrong.  It's doing the
exact opposite of lazy loading.  Maybe they were trying to use AI code
gen before it existed?

Bug: b/348024314
Change-Id: I068d43fe1abf757cb8b109890a14ca0cefe3fec0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5641090
Commit-Queue: Allen Li <ayatane@chromium.org>
Reviewed-by: Yiwei Zhang <yiwzhang@google.com>

git_cl.py

@@ -2202,7 +2202,7 @@ class Changelist(object):
             raise
 
     def GetGerritHost(self):
-        # Lazy load of configs.
+        # Populate self._gerrit_host
         self.GetCodereviewServer()
 
         if self._gerrit_host and '.' not in self._gerrit_host: