Fix lang selection

lib/ui/widgets/banner_widget.dart

@@ -48,8 +48,8 @@ class _BannerWidgetState extends State<BannerWidget> {
             ),
             Flexible(
               child: Text(
-                banner.message.containsKey(lang())
-                    ? banner.message[lang()]
+                banner.message.containsKey(shortLang)
+                    ? banner.message[shortLang]
                     : banner.message["en"],
                 style: TextStyle(color: Colors.white),
               ),

lib/utils/intl_utils.dart

@@ -49,7 +49,9 @@ String tr(String string, {Map<String, String> args}) {
   return string;
 }
 
-/// Get current lang
-String lang() {
-  return _currLang != null ? _currLang : "en";
-}
+/// Get current lang, in format aa_BB
+String get lang => _currLang != null ? _currLang : "en_US";
+
+
+/// Get short lang format, in format aa
+String get shortLang => lang.split("_")[0];