sdpmessage: Annotate SDP message parameters for `parse_uri()` and `parse_buffer()` correctly
They are not actually out
parameters but must be allocated and
initialized to a valid SDP message by the caller. Just allocating them
without initialization will cause memory corruptions because the
functions will try to clear/append to the existing SDP message.
As such they should be just marked as transfer none
.
Fixes #1605 (closed)