Add mapseed to get_server_info table

src/script/lua_api/l_client.cpp

@@ -332,6 +332,8 @@ int ModApiClient::l_get_server_info(lua_State *L)
 	lua_setfield(L, -2, "port");
 	lua_pushinteger(L, client->getProtoVersion());
 	lua_setfield(L, -2, "protocol_version");
+	lua_pushinteger(L, client->getMapSeed());
+	lua_setfield(L, -2, "seed");
 	return 1;
 }