[win-bootstrap] Expand comment for auto-configured early exit

Bug: b/382395049
Change-Id: Ic45c472931c438eb16934cb17c13856b06a776bb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6072986
Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
Reviewed-by: Allen Li <ayatane@chromium.org>
Commit-Queue: Anne Redulla <aredulla@google.com>

bootstrap/bootstrap.py

@@ -357,7 +357,8 @@ def _win_git_bootstrap_config():
     postprocess_version = get_git_global_config_value(git_path=git_bat_path,
                                                       key=postprocess_key)
     if postprocess_version == GIT_POSTPROCESS_VERSION:
-        # Already configured. Nothing to do.
+        # Previously configured automatically by depot_tools at the current
+        # version of the global git config. Nothing to do.
         return
 
     # Check whether the user has authorized depot_tools to update their global