config_transport: Fix objects returned by ast_sip_get_transport_states
ast_sip_get_transport_states was returning a container of internal_state
objects instead of ast_sip_transport_state objects. This was causing
transport lookups to fail, most noticably in res_pjsip_nat, which
couldn't find the correct external addresses. This was causing contacts
to go out with internal ip addresses.
ASTERISK-25830 #close Reported-by: Sean Bright
Change-Id: I1aee6a2fd46c42e8dd0af72498d17de459ac750e