tp_base_contact_list_group_renamed: fix thinko when creating new channels
tp_base_contact_list_group_renamed: fix thinko when creating new channels

There's no point in redoing the hash table lookup until after we've
(hopefully) created the channel.

Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib