Fixed hotkey prefs being lost after installing addons (fixes #2532)

The problem was that game_config_manager::init_game_config was called (via reload_changed_game_config)
after an addon was installed, which loaded the standard game-defined hotkeys. The loading of hotkey
preferences was relegated to the main game loop (do_gameloop). However, that loop wasn't entered again
when installing addons, since technically you never left the titlescreen, so the default hotkeys were
being re-loaded but not the prefs one.

I've moved loading of both to the same place to prevent any further issues.

src/game_config_manager.cpp

@@ -93,7 +93,10 @@ bool game_config_manager::init_game_config(FORCE_RELOAD_CONFIG force_reload)
 	hotkey::deactivate_all_scopes();
 	hotkey::set_scope_active(hotkey::SCOPE_MAIN_MENU);
 
+	// Load the standard hotkeys, then apply any player customizations.
 	hotkey::load_hotkeys(game_config(), true);
+	//preferences::load_hotkeys();
+
 	::init_textdomains(game_config());
 	about::set_about(game_config());
 	ai::configuration::init(game_config());

src/wesnoth.cpp

@@ -828,8 +828,6 @@ static int do_gameloop(const std::vector<std::string>& args)
 			return 0;
 		}
 
-		preferences::load_hotkeys();
-
 		const font::floating_label_context label_manager;
 
 		cursor::set(cursor::NORMAL);