Disabled i18next debug mode in development

- I didn't realise how annoying this would be so this commit disables it

ghost/i18n/lib/i18n.js

@@ -10,7 +10,6 @@ module.exports = (lng = 'en', ns = 'portal') => {
     const i18nextInstance = i18next.createInstance();
     i18nextInstance.init({
         lng,
-        debug: process.env.NODE_ENV === 'development',
 
         // allow keys to be phrases having `:`, `.`
         nsSeparator: false,