I don't see the point of inserting p_proto_data sorted use
g_slist_prepend().
While there fix deprecated API.

Change-Id: Id5241348927d904d859530fac3f43f2b301a1acb
Reviewed-on: https://code.wireshark.org/review/2982
Reviewed-by: Anders Broman <a.broman58@gmail.com>