[SR-Users] Manipulation of request-line

Hi, I have an issue with a SIP-client, that occasionally puts a blank between the version SIP/2.0 and the CRLF at the and of the request-line. (i.e. sends "ACK <uri> SIP/2.0 \r\n" instead of "ACK <uri> SIP/2.0\r\n"). Kamailio (as well as most SIP UAs) does not care about that error and successfully processes/forwards the request (also when using sanity_check()). But I also deal with a client that fails to parse that request. (Furthermore, wireshark's dissector fails to recognize such malformed messages as SIP, which makes debugging even harder). I tried to fix this issue using textops, but all functions I tried operate only on headers or message body, but do not seem to affect the request line. Is there any possibility to modify the request-line, or to replace it with a new one? Best Regards, Mihovil