net-mgmt/collectd5: fix typo and add patch for Varnish 4.1 compatability

• Fix copy/paste typo in XML_LIB_DEPENDS [1]
• Add patch for building with varnish4-4.1 and drop VARNISH_BROKEN [2]
• Bump PORTREVISION for package change with XML_LIB_DEPENDS option

PR: 204608 [1]
PR: 204583 [2]
Reported by: rhavenn@rhavenn.net [1]
Submitted by: feld [2]
Obtained from: https://github.com/mfournier/collectd [2]
Approved by: Krzysztof <ports@bsdserwis.com> (maintainer)