Remove incorrect comma. (pythonGH-19604)

Doc/tools/templates/layout.html

@@ -3,7 +3,7 @@
 {%- if outdated %}
 <div id="outdated-warning" style="padding: .5em; text-align: center; background-color: #FFBABA; color: #6A0E0E;">
     {% trans %}This document is for an old version of Python that is {% endtrans %}<a href="https://devguide.python.org/devcycle/#end-of-life-branches">{% trans %}no longer supported{% endtrans %}</a>.
-    {% trans %}You should upgrade, and read the {% endtrans %}
+    {% trans %}You should upgrade and read the {% endtrans %}
     <a href="https://docs.python.org/{{ language + '/' if language and language != 'en' else '' }}3/{{ pagename }}{{ file_suffix }}">{% trans %} Python documentation for the current stable release{% endtrans %}</a>.
 </div>
 {%- endif %}