Connection: assume all handles have ContactCaps
Connection: assume all handles have ContactCaps

Previously, some places in Gabble which called
gabble_connection_get_handle_contact_capabilities() did not assume that
it never returns NULL. But (due to the implicit text caps for everyone)
it is guaranteed always to return a non-NULL array of capabilities, so
we can simplify the places that call it.

mlundblad/telepathy-gabble,Ziemin/telepathy-gabble,Ziemin/telepathy-gabble,mlundblad/telepathy-gabble,Ziemin/telepathy-gabble,mlundblad/telepathy-gabble,Ziemin/telepathy-gabble