www/librewolf: correct the package description

WWW within Makefile is correct.

Remove the WWW line (with a different URL) from pkg-descr.

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=258503#c32

PR: 258503
Reported by: VVD at comment 32
Fixes: 4e77dee79c17 www/librewolf: New port