[BUGFIX] Only request locale file once

lib/main.js

@@ -82,8 +82,9 @@ define(['moment', 'utils/router', 'leaflet', 'gui', 'helper', 'utils/language'],
         }
       }
 
-      function update() {
       language.init(router);
+
+      function update() {
         return Promise.all(urls.map(helper.getJSON))
           .then(handleData);
       }