Fix bug #9021, Game Lobby Color Translation Error.

More generally, reload [game_config] when switching language, so any 
translatable string defined there is reloaded in the new language.
Also reset server list when reloading [game_config] because it builded up.

src/game.cpp

@@ -1677,6 +1677,9 @@ void game_controller::refresh_game_cfg(bool reset_translations)
 				read_game_cfg(defines_map_, game_config_, use_caching_);
 			} else {
 				game_config_.reset_translation();
+				// we may have translatable strings in [game_config]
+				// e.g. team color names are defined there
+				game_config::load_config(game_config_.child("game_config"));
 			}
 
 			const config* const units = game_config_.child("units");

src/game_config.cpp

@@ -182,6 +182,7 @@ namespace game_config
 			defense_color_scale.push_back(0x00FFFF00);
 		}
 
+		server_list.clear();
 		const std::vector<config *> &servers = v.get_children("server");
 		std::vector<config *>::const_iterator server;
 		for(server = servers.begin(); server != servers.end(); ++server) {