gerrit_util: Delete temporary text about auth testing setup

Change-Id: I6c61998c1fca2681f6dc0f33468a8ae5b378f12e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/6306289
Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
Commit-Queue: Allen Li <ayatane@chromium.org>

gerrit_util.py

@@ -336,16 +336,7 @@ def ensure_authenticated(gerrit_host: str, git_host: str) -> Tuple[bool, str]:
 
 
 class SSOAuthenticator(_Authenticator):
-    """SSOAuthenticator implements a Google-internal authentication scheme.
-
-    TEMPORARY configuration for Googlers (one `url` block for each Gerrit host):
-
-        [url "sso://chromium/"]
-          insteadOf = https://chromium.googlesource.com/
-          insteadOf = http://chromium.googlesource.com/
-        [depot-tools]
-          useNewAuthStack = 1
-    """
+    """SSOAuthenticator implements a Google-internal authentication scheme."""
 
     # This is set to true in tests, allows _parse_config to consume expired
     # cookies.