* doc/xml/gnu/gpl-3.0.xml: Switch www.gnu.org to https.

From-SVN: r277435

libstdc++-v3/ChangeLog

+2019-10-25  Gerald Pfeifer  <gerald@pfeifer.com>
+
+	* doc/xml/gnu/gpl-3.0.xml: Switch www.gnu.org to https.
+
 2019-09-09  Edward Smith-Rowland  <3dw4rd@verizon.net>
 
 	* doc/xml/manual/status_cxx2020.xml: Add rows and update status.

libstdc++-v3/doc/xml/gnu/gpl-3.0.xml

@@ -829,6 +829,6 @@ under certain conditions; type ‘<literal>show c</literal>’ for details.
     subroutine library, you may consider it more useful to permit linking
     proprietary applications with the library.  If this is what you want to do,
     use the <acronym>GNU</acronym> Lesser General Public License instead of this
-    License.  But first, please read <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.gnu.org/philosophy/why-not-lgpl.html">http://www.gnu.org/philosophy/why-not-lgpl.html</link>.
+    License.  But first, please read <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="https://www.gnu.org/philosophy/why-not-lgpl.html">https://www.gnu.org/philosophy/why-not-lgpl.html</link>.
   </para>
 </appendix>