net/lavinmq: Remove obsolete WWW: lines from pkg-descr
The WWW: lines at the end of pkg-descr files has been replaced
by the WWW macro in the ports' Makefiles on September 7, 2022
(see commit b7f05445c00f26 for details).
Approved by: portmgr (implicit)
net/lavinmq: new port AMQP-compliant message broker
High performance AMQP-0.9.1 compatible, written in Crystal.
Differential Revision: https://reviews.freebsd.org/D31410