Log Message:
Update ruby-nokogiri to 1.6.7.2.

Below security problem dose not affect to pkgsrc since we do not use bundlerd
libxml2.

=== 1.6.7.2 / 2015-01-20

This version pulls in several upstream patches to the vendored libxml2 and \ 
libxslt to address:

  CVE-2015-7499

Ubuntu classifies this as "Priority: Low", RedHat classifies this as \ 
"Impact: Moderate", and NIST classifies this as "Severity: 5.0 \ 
(MEDIUM)".

MITRE record is https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-7499