Now really use the taskbar icon from game_config.cfg, and fix its url.

It was ignored before and only the hardcoded one was used. It is still
used during loading, but when game_config is loaded, now use the one
specidied there. Maybe not the final solution but documented the
problem.

data/game_config.cfg

@@ -29,7 +29,7 @@
     #
     title="maps/wesnoth.png"
     logo="misc/logo.png"
-    icon="wesnoth-icon.png"
+    icon="wesnoth-icon-small.png"
     title_music="main_menu.ogg"
     lobby_music="silence.ogg"
 

src/game.cpp

@@ -536,6 +536,7 @@ bool game_controller::init_video()
 		return true;
 	}
 
+	//NOTE will use the hardcoded icon, game_config is not ready yet
 	image::set_wm_icon();
 
 	std::pair<int,int> resolution;
@@ -596,6 +597,10 @@ bool game_controller::init_config(const bool force)
 
 	const config &cfg = game_config().child("game_config");
 	game_config::load_config(cfg ? &cfg : NULL);
+
+	//the game_config icon may be different from the hardcoded one
+	image::set_wm_icon();
+
 	hotkey::deactivate_all_scopes();
 	hotkey::set_scope_active(hotkey::SCOPE_GENERAL);
 	hotkey::set_scope_active(hotkey::SCOPE_GAME);

src/game_config.cpp

@@ -63,7 +63,8 @@ namespace game_config
 			default_defeat_music;
 
 	namespace images {
-	std::string game_icon,
+	//NOTE hardcode game_icon because used before that game_config is ready
+	std::string game_icon = "wesnoth-icon-small.png",
 			game_title,
 			game_logo,
 			// orbs and hp/xp bar