docs: https all the links \o/

Most of them already redirected to https anyway, so we might as well
avoid the redirection and the security implications by linking directly
to the right protocol.

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Brian Paul <brianp@vmware.com>

docs/utilities.html

@@ -17,11 +17,11 @@
 <h1>Development Utilities</h1>
 
 <dl>
-  <dt><a href="http://cgit.freedesktop.org/mesa/demos">Mesa demos collection</a></dt>
+  <dt><a href="https://cgit.freedesktop.org/mesa/demos">Mesa demos collection</a></dt>
   <dd>includes several utility routines in the <code>src/util/</code>
   directory.</dd>
 
-  <dt><a href="http://piglit.freedesktop.org">Piglit</a></dt>
+  <dt><a href="https://piglit.freedesktop.org">Piglit</a></dt>
   <dd>is an open-source test suite for OpenGL implementations.</dd>
 
   <dt><a href="https://github.com/apitrace/apitrace">ApiTrace</a></dt>
@@ -31,7 +31,7 @@
   <dd>is a very useful tool for tracking down
   memory-related problems in your code.</dd>
 
-  <dt><a href="http://scan.coverity.com/projects/mesa">Coverity</a><dt>
+  <dt><a href="https://scan.coverity.com/projects/mesa">Coverity</a><dt>
   <dd>provides static code analysis of Mesa.  If you create an account
   you can see the results and try to fix outstanding issues.</dd>
 </dl>