[update] sysutils/burp to 2.4

Hello,

Here is port for Burp in version 2.4.0.


I already sent a 2.3 version that never got commited:
https://marc.info/?l=openbsd-ports&m=157356543829925


I think we can kill version 2.0, and maybe version 2.1 as well.

Thanks,
Best.

--
Olivier Cherrier
Phone: +352691570680
mailto:oc@symacx.com