tubes-manager: don't fire NewChannel signal in new_tubes_channel
tubes-manager: don't fire NewChannel signal in new_tubes_channel

freedesktop-unofficial-mirror/telepathy__telepathy-salut,freedesktop-unofficial-mirror/telepathy__telepathy-salut,freedesktop-unofficial-mirror/telepathy__telepathy-salut,freedesktop-unofficial-mirror/telepathy__telepathy-salut