Issue #26736: Used HTTPS for external links in the documentation if possible.
diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst
index 6f8b7af..80f3635 100644
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -1273,7 +1273,7 @@
(:mod:`httplib` then also transparently sends an IDNA hostname in the
:mailheader:`Host` field if it sends that field at all).
-.. _section 3.1: http://tools.ietf.org/html/rfc3490#section-3.1
+.. _section 3.1: https://tools.ietf.org/html/rfc3490#section-3.1
When receiving host names from the wire (such as in reverse name lookup), no
automatic conversion to Unicode is performed: Applications wishing to present