[wwwdocs] www.openacc.org switched to https

[Gerald Pfeifer]

Applied.

Gerald

Index: htdocs/gcc-6/changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-6/changes.html,v
retrieving revision 1.99
diff -u -r1.99 changes.html
--- htdocs/gcc-6/changes.html	7 Apr 2017 07:16:59 -0000	1.99
+++ htdocs/gcc-6/changes.html	10 Jun 2017 09:07:24 -0000
@@ -136,7 +136,7 @@
 
 <!-- <ul>
   <li> -->Compared to GCC 5, the GCC 6 release series includes a much improved
-    implementation of the <a href="http://www.openacc.org/">OpenACC 2.0a
+    implementation of the <a href="https://www.openacc.org">OpenACC 2.0a
       specification</a>.  Highlights are:
     <ul>
       <li>In addition to single-threaded host-fallback execution, offloading is