### Description

In python (using module app_python3), in the xhttp module event callback (ksr_xhttp_event):

``` KSR.xhttp.xhttp_reply(400, "Bad Request", "", "") return 1 ```

When this code is processed, Kamailio logs the following errors: ``` 6(247453) ERROR: <core> [core/parser/parse_fline.c:272]: parse_first_line(): parse_first_line: bad message (offset: 16) 6(247453) ERROR: <core> [core/parser/msg_parser.c:749]: parse_msg(): ERROR: parse_msg: message=<HTTP/1.1 400 Bad Request Sia: SIP/2.0/TCP 127.0.0.1:41706 Server: kamailio (5.7.1 (x86_64/linux)) Content-Length: 0

6(247453) ERROR: <core> [core/msg_translator.c:3256]: build_sip_msg_from_buf(): parsing failed ``` (The correct HTTP reply is sent back to the client, so the issue is only with these logs.)

<br>

In kamailio script, in event_route[xhttp:request]: ``` xhttp_reply("400", "Bad Request", "", ""); exit; ``` In this case, there are no errors in Kamailio logs.

The two should be equivalent, but when using python we get errors when trying to send a specific HTTP reply.

<br>

When using python, if calling "KSR.jsonrpcs.dispatch()" for an unknown method, we get the same errors in Kamailio logs: ``` 6(253511) ERROR: <core> [core/parser/parse_fline.c:272]: parse_first_line(): parse_first_line: bad message (offset: 19) 6(253511) ERROR: <core> [core/parser/msg_parser.c:749]: parse_msg(): ERROR: parse_msg: message=<HTTP/1.1 500 Method Not Found Sia: SIP/2.0/TCP 127.0.0.1:59048 Content-Type: application/json Server: kamailio (5.7.1 (x86_64/linux)) Content-Length: 84

{ "jsonrpc": "2.0", "error": { "code": 500, "message": "Method Not Found" } }> 6(253511) ERROR: <core> [core/msg_translator.c:3256]: build_sip_msg_from_buf(): parsing failed ```

When the method is correct (client receives a HTTP 200), there are no errors in Kamailio logs.

<br>

### Additional Information

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

``` version: kamailio 5.7.1 (x86_64/linux) 4238e4 flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, MEM_JOIN_FREE, 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_BLOCKLIST, HAVE_RESOLV_RES, TLS_PTHREAD_MUTEX_SHARED 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: 4238e4 compiled on 16:52:41 Aug 24 2023 with gcc 8.5.0 ```