Filter out CDATA tag for RSS feeds (#691)

* add cdata regex

* remove cdata via regex

* add trailing comma

* fix no-useless-escape

* switch let to const

shared/util/regEx.js

@@ -1,6 +1,7 @@
 const regEx = {
   url: /^(?:https?|ftp):\/\/.{1,}\.{1}.{1,}/,
   domainName: /(?:https?|udp):\/\/(?:www\.)?([-a-zA-Z0-9@:%._+~#=]{2,256}\.[a-z]{2,18}\b)*(\/[/\d\w.-]*)*(?:[?])*(.+)*/i,
+  cdata: /<!\[CDATA\[(.*?)\]\]>/,
 };
 
 module.exports = regEx;