Comment 9 for bug 634571

The attached patch fixes the problem, which is twofold:

a) vncconnection.c#vnc_connection_perform_auth_tls incorrectly emits a signal to set the primary authentication type instead of the subtype

b) vncdisplay.c#on_auth_choose_subtype incorrectly calls vnc_connection_set_auth_type instead of vnc_connection_set_auth_subtype.