Log Message:
www/ruby-rails61: update to 6.1.4.7

Ruby on Rails 6.1.4.7 is not latest version but it should be easy to pull-up
to pkgsrc-2021Q4.

Changes are in devel/ruby-activestorage61 only.

## Rails 6.1.4.7 (March 08, 2022) ##

* Added image transformation validation via configurable allow-list.

 Variant now offers a configurable allow-list for
 transformation methods in addition to a configurable deny-list for arguments.

 [CVE-2022-21831]