[sr-dev] [kamailio/kamailio] when use pcscf_unregister behind nat (#2729)

### Description <!-- --> ``` As you can see in the picture, via_host and received_host are different when sending registration data from outside of NAT. However, in the pcscf_unregister function, via_host and received_host are the same value.The pcontact structure in memory could not be found ``` #### Log Messages <!-- Check the syslog file and if there are relevant log messages printed by Kamailio, add them next, or attach to issue, or provide a link to download them (e.g., to a pastebin site). --> ```   ``` ### Possible Solutions <!-- If you found a solution or workaround for the issue, describe it. Ideally, provide a pull request with a fix. --> ``` change the pcscf_unregister function, and add Two parameters ``` ### Additional Information * **Kamailio Version** - output of `kamailio -v` ``` version: kamailio 5.4.4 (x86_64/linux) 8d6c2b flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: 8d6c2b compiled on 14:04:08 Apr 26 2021 with gcc 4.8.5 ``` * **Operating System**: <!-- Details about the operating system, the type: Linux (e.g.,: Debian 8.4, Ubuntu 16.04, CentOS 7.1, ...), MacOS, xBSD, Solaris, ...; Kernel details (output of `uname -a`) --> ``` Linux iZhp329ygro5y3v090vnwpZ 3.10.0-957.21.3.el7.x86_64 #1 SMP Tue Jun 18 16:35:19 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux ``` -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/kamailio/kamailio/issues/2729