### Description
I tried using the Kamailio as a sip capture node, with TCP and captagent sending data to it using HEP3 protocol
#### Reproduction
send sip traffic to the Kamailio node over tcp - hep3
#### SIP Traffic
<!-- If the issue is exposed by processing specific SIP messages, grab them with ngrep or save in a pcap file, then add them next, or attach to issue, or provide a link to download them (e.g., to a pastebin site). -->
``` T 10.62.232.8:59218 -> 172.17.0.2:9060 [AP] HEP3..................................... Y...... . ................ .........
.......
"./.......myhep.....SOPTIONS sip:34.222.33.444:5060 SIP/2.0. Via: SIP/2.0/UDP 34.222.33.444:5060;branch=z9hG4bKadc3.94894fb2.0. To: sip:34.222.33.444:5060. From: sip:dispatcher@localhost;tag=8176c6985887ae1fa077926d61f38185-6330. CSeq: 14 OPTIONS. Call-ID: 524281af251ad3ae-5781@10.62.232.8. Max-Forwards: 70. Content-Length: 0. User-Agent: user. .
ERROR MSG:
############### 8(16359) ERROR: <core> [core/tcp_read.c:1391]: tcp_read_req(): bad request, state=7, error=4 buf: HEP3� parsed: HEP3� ```
### Additional Information
* **Kamailio Version** - output of `kamailio -v`
``` version: kamailio 5.1.0-dev8 (x86_64/linux) flags: STATS: Off, USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MEM, 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_LISTEN 16, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: unknown compiled on 15:58:15 Nov 1 2017 with gcc 4.9.2 ```
* **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 15e97661fc7f 4.9.43-17.39.amzn1.x86_64 #1 SMP Fri Sep 15 23:39:41 UTC 2017 x86_64 GNU/Linux ```
I saw it on the master branch updated to 1/11/2017 I also saw it was addressed before, but it still doesn't seem to work for me, am I missing something?
https://github.com/kamailio/kamailio/issues/599