new_connection_to_socket: fix transport leak
new_connection_to_socket: fix transport leak

jku/telepathy-gabble,mlundblad/telepathy-gabble,Ziemin/telepathy-gabble,Ziemin/telepathy-gabble,community-ssu/telepathy-gabble,mlundblad/telepathy-gabble,mlundblad/telepathy-gabble,jku/telepathy-gabble,Ziemin/telepathy-gabble,Ziemin/telepathy-gabble,community-ssu/telepathy-gabble,community-ssu/telepathy-gabble,jku/telepathy-gabble,community-ssu/telepathy-gabble