[ci skip] Try to decrease complexity

src/main/java/fr/xephi/authme/util/message/I18NUtils.java

@@ -91,11 +91,15 @@ public class I18NUtils {
             //    return "zhmc";
         }
 
+        // Match locale code with "_"
+        return matchLocale(locale, settings);
+    }
+
+    private static String matchLocale(String locale, Settings settings) {
         if (locale.contains("_")) {
             locale = locale.substring(0, locale.indexOf("_"));
         }
 
-        // Match locale code with "_"
         if (LOCALE_LIST.contains(locale)) {
             return locale;
         }