whois: trim output after ">>> Last update of WHOIS database:"

whois: trim output after ">>> Last update of WHOIS database:"
Currently, whois(1) displays the full output it receives from the
server.  With this change, any text after a line starting with ">>>
Last update of WHOIS database:" is dropped.  This trims a lot of
useless text that would otherwise cause the data you care about to
scroll off the screen.  From FreeBSD.  OK deraadt@