footer.html: Shorten if condition for MathJAX (#40)

Signed-off-by: Stephan Kulla <git.mail@kulla.me>

layouts/partials/footer.html

@@ -34,7 +34,7 @@
     <script>hljs.initHighlightingOnLoad();</script>
 
     <!-- LaTeX math rendering -->
-    {{ if or (and (isset .Site.Params "math") (eq .Site.Params.math true)) (and (isset .Params "math") (eq .Params.math true)) }}
+    {{ if or .Params.math .Site.Params.math }}
     <script type="text/x-mathjax-config">
         MathJax.Hub.Config({ tex2jax: { inlineMath: [['$','$'], ['\\(','\\)']] } });
     </script>