Remove prism fix for html and js code blocks

js/background/markdown.js

@@ -25,10 +25,6 @@ var md = (function () {
 
       marked(markdown, function (err, html) {
         if (err) throw err
-        // prism fix
-        html = html.replace(/language-html/g, 'language-markup')
-        html = html.replace(/language-js/g, 'language-javascript')
-
         sendResponse({message: 'marked', marked: html})
       })
     })