[wwwdocs] readings.html - move www.adaic.org reference to https

[Gerald Pfeifer]

...like the others.

Committed.

Gerald

Index: readings.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/readings.html,v
retrieving revision 1.316
diff -u -r1.316 readings.html
--- readings.html       28 Jul 2019 08:54:12 -0000      1.316
+++ readings.html       30 Jul 2019 22:13:35 -0000
@@ -568,7 +568,7 @@
    <li><a href="https://www.adacore.com/community";>AdaCore Community 
Site</a></li>
    <li><a href="https://www2.adacore.com/gap-static/GNAT_Book/html/";>GNAT:
    The GNU Ada Compiler</a></li>
-   <li><a 
href="http://www.adaic.org/resources/add_content/docs/95style/html/cover.html";>Ada
+   <li><a 
href="https://www.adaic.org/resources/add_content/docs/95style/html/cover.html";>Ada
    Quality &amp; Style Guide</a></li>
    <li><a 
href="http://www.sigada.org/ada_letters/jun2004/ravenscar_article.pdf";>Guide
    for the use of the Ada Ravenscar Profile in high integrity