Removed the core file path from the preferences.

The new implementation works with the id only.

src/preferences.cpp

@@ -234,16 +234,6 @@ void set_allied_color(const std::string& color_id) {
 	prefs["ally_orb_color"] = color_id;
 }
 
-std::string wml_tree_root() {
-	std::string wml_tree_root = get("wml_tree_root");
-	if (wml_tree_root.empty())
-		return "_main.cfg";
-	return wml_tree_root;
-}
-void set_wml_tree_root(const std::string& wml_tree_root) {
-	prefs["wml_tree_root"] = wml_tree_root;
-}
-
 std::string core_id() {
 	std::string core_id = get("core");
 	if (core_id.empty())

src/preferences.hpp

@@ -55,9 +55,6 @@ namespace preferences {
 
 	config* get_prefs();
 
-	std::string wml_tree_root();
-	void set_wml_tree_root(const std::string& root);
-
 	std::string core_id();
 	void set_core_id(const std::string& root);
 

src/wesnoth.cpp

@@ -762,9 +762,7 @@ static int do_gameloop(const std::vector<std::string>& args)
 			gui2::tcore_selection core_dlg(cores, current);
 			if (core_dlg.show(game->disp().video())) {
 				int core_index = core_dlg.get_choice();
-				const std::string& wml_tree_root = cores[core_index]["path"];
 				const std::string& core_id = cores[core_index]["id"];
-				preferences::set_wml_tree_root(wml_tree_root);
 				preferences::set_core_id(core_id);
 				config_manager.reload_changed_game_config();
 			}