### Description

Added IPv6 listeners into the default config file. ``` listen=udp:[2600:1f18:63e1:6936::300]:5060 listen=tcp:[2600:1f18:63e1:6936::300]:5060 ``` Kamailio is able receive REGISTER messages. But ignores `OPTIONS`. When `#!define WITH_DEBUG` kamailio shows nothing on `OPTIONS` messages.

### Troubleshooting

#### Reproduction

1) add IPv6 listeners into default config 2) send OPTIONS messages to kamailio.

#### Debugging Data None

#### Log Messages None

#### SIP Traffic Kamailio receive this OPTIONS messages

``` OPTIONS sip:proxy-0.wv.example.com:5080 SIP/2.0 Via: SIP/2.0/UDP [2600:1F1C:257:8706:ACAB:AE:2A01:1EA3];branch=z9hG4bK2b03.70dce6f2000000000000000000000000.0 To: sip:proxy-0.wv.example.com:5080 From: sip:proxy@aggregator.example.com;tag=44bcb2ee24537bd62851129efb658b7a-17d18de8 CSeq: 10 OPTIONS Call-ID: 59605197726e91db-2653@172.22.6.201 Max-Forwards: 70 Content-Length: 0 User-Agent: kamailio (5.5.0-dev1 (x86_64/linux)) ```

### Possible Solutions Not known

### Additional Information

* **Kamailio Version** - output of `kamailio -v`

``` [root@proxy-0 ~]# kamailio -v version: kamailio 5.5.0-dev1 (x86_64/linux) c960ca 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: c960ca compiled on 04:08:19 Aug 20 2020 with gcc 4.8.5 ```

* **Operating System**: ``` [root@proxy-0 ~]# cat /etc/os-release NAME="CentOS Linux" VERSION="7 (Core)" ID="centos" ID_LIKE="rhel fedora" VERSION_ID="7" PRETTY_NAME="CentOS Linux 7 (Core)" ANSI_COLOR="0;31" CPE_NAME="cpe:/o:centos:centos:7" HOME_URL="https://www.centos.org/" BUG_REPORT_URL="https://bugs.centos.org/"

CENTOS_MANTISBT_PROJECT="CentOS-7" CENTOS_MANTISBT_PROJECT_VERSION="7" REDHAT_SUPPORT_PRODUCT="centos" REDHAT_SUPPORT_PRODUCT_VERSION="7" ```