Delete empty file

lib/battle/AutocombatPreferences.cpp

@@ -1,11 +0,0 @@
-/*
- * AutocombatPreferences.cpp, part of VCMI engine
- *
- * Authors: listed in file AUTHORS in main folder
- *
- * License: GNU General Public License v2.0 or later
- * Full text of license available in license.txt file, in main folder
- *
- */
-
-#include "AutocombatPreferences.h"