Remove comment about a private email.headerregistry (GH-24233)

The-Compiler · web-flow · commit 70f8ebe503fc · 2021-02-24T17:21:32.000-04:00
It's been public since 2012: ea97668
diff --git a/Lib/email/headerregistry.py b/Lib/email/headerregistry.py
@@ -2,10 +2,6 @@
 
 This module provides an implementation of the HeaderRegistry API.
 The implementation is designed to flexibly follow RFC5322 rules.
-
-Eventually HeaderRegistry will be a public API, but it isn't yet,
-and will probably change some before that happens.
-
 """
 from types import MappingProxyType
 
