Added dbus error register for dbus error invocation

Added dbus error register for dbus error invocation

E/WIFI_MANAGER( 1241): network_interface.c: net_config_get_id_list(2780) > Failed to get config id list. Error [NET_ERR_UNKNOWN]
E/WIFI_MANAGER( 1241): wifi_internal.c: _wifi_load_configurations(2144) > Fail to load configurations [-30277631]
E/WIFI_MANAGER( 1241): wifi_config.c: wifi_manager_config_foreach_configuration(236) > Fail to load configurations [-3027763

Change-Id: Idd0658b61fcbda631a287ee77bee4094dd8fd3db
Signed-off-by: Taesub Kim <taesub.kim@samsung.com>