Fix Python version since which external enities are not resolved by default. (GH-11237)

diff --git a/Doc/library/xml.sax.rst b/Doc/library/xml.sax.rst
index 0b6973b..6d351df 100644
--- a/Doc/library/xml.sax.rst
+++ b/Doc/library/xml.sax.rst
@@ -24,7 +24,7 @@
    constructed data.  If you need to parse untrusted or unauthenticated data see
    :ref:`xml-vulnerabilities`.
 
-.. versionchanged:: 3.8
+.. versionchanged:: 3.7.1
 
    The SAX parser no longer processes general external entities by default
    to increase security. Before, the parser created network connections