Fix `PlayersParser` not properly cleaning `EPlayer` reference

sources/Commands/PlayersParser.uc

@@ -101,6 +101,7 @@ protected function Finalizer()
 public final function SetSelf(EPlayer newSelfPlayer)
 {
     _.memory.Free(selfPlayer);
+    selfPlayer = none;
     if (newSelfPlayer != none) {
         selfPlayer = EPlayer(newSelfPlayer.Copy());
     }