net/kamailio: upgrade 5.2.0 -> 5.2.4
Relnotes: https://www.kamailio.org/w/2019/08/kamailio-v5-2-4-released/
https://www.kamailio.org/w/2019/05/kamailio-v5-2-3-released/ https://www.kamailio.org/w/2019/03/kamailio-v5-2-2-released/ https://www.kamailio.org/w/2019/01/kamailio-v5-2-1-released/