Bump PORTREVISION for libxml2 update
Nokogiri gives out warning when libxml2 version changed.
WARNING: Nokogiri was built against LibXML version 2.9.4, but has dynamically loaded 2.9.7
Bump PORTREVISION to rebuild with latest libxml2.
PR: 224377
Submitted by: Matthias Fechner <idefix@fechner.net>