fix: Canonicalize locale codes

client/src/locales/index.js

@@ -24,8 +24,8 @@ import ptBR from './pt-BR';
 import roRO from './ro-RO';
 import ruRU from './ru-RU';
 import skSK from './sk-SK';
-import srCyrlCS from './sr-Cyrl-CS';
-import srLatnCS from './sr-Latn-CS';
+import srCyrlRS from './sr-Cyrl-RS';
+import srLatnRS from './sr-Latn-RS';
 import svSE from './sv-SE';
 import trTR from './tr-TR';
 import ukUA from './uk-UA';
@@ -55,8 +55,8 @@ const locales = [
   roRO,
   ruRU,
   skSK,
-  srCyrlCS,
-  srLatnCS,
+  srCyrlRS,
+  srLatnRS,
   svSE,
   trTR,
   ukUA,