Description: Use Debian mathjax package

Using remote resources in locally-installed documentation is discouraged
for privacy reasons (lintian error: privacy-breach-may-use-debian-package).

Recommend: rather than Depend: libjs-mathjax because browsers with
native MathML support (e.g. iceweasel) don't need it.

Author: Rebecca Palmer <rebecca_palmer@zoho.com>
Bug-Debian: https://bugs.debian.org/770600

--- a/html/opengl-man.xsl
+++ b/html/opengl-man.xsl
@@ -65,7 +65,7 @@
             });
         </script>
         <script type="text/javascript"
-            src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML">
+            src="file:///usr/share/javascript/mathjax/MathJax.js?config=TeX-AMS-MML_HTMLorMML">
         </script>
     </xsl:template>