MT#60476 sdp_origin: always update origin from sdp
Independently from the fact if a monologue already
has the `->session_sdp_orig` object set, update it
accordingly to the latest origin taken from
the currently processed SDP.
In this case such option flags as `replace_origin`,
`replace_origin_full` or `force_inc_sdp_ver` are
ignored, because their handling is covered using
the `->session_last_sdp_orig` object.
Change-Id: Ib845d185a03a2cb99ead5f6039342388c461cee2