Move custom loader to main.jsx

So that it's only done once.

src/lib/render.jsx

@@ -2,17 +2,11 @@ var ReactDOM = require('react-dom');
 var ReactIntl = require('react-intl');
 var IntlProvider = ReactIntl.IntlProvider;
 
-var customLanguages = require('./custom-locales.json');
-
 var render = function (jsx, element) {
     // Get locale and messages from global namespace (see "init.js")
     var locale = window._locale;
     var messages = window._translations[locale];
 
-    if (customLanguages[locale] !== undefined) {
-        ReactIntl.addLocaleData(customLanguages[locale]);
-    }
-
     // Render component
     var component = ReactDOM.render(
         <IntlProvider locale={locale} messages={messages}>