add player.locale (#4633)

core/src/mindustry/entities/comp/PlayerComp.java

@@ -41,6 +41,7 @@ abstract class PlayerComp implements UnitController, Entityc, Syncc, Timerc, Dra
     boolean admin;
     @SyncLocal float mouseX, mouseY;
     String name = "noname";
+    String locale = "en";
     Color color = new Color();
 
     transient float deathTimer;