www/ruby-rails52: update to 5.2.6.3

Ruby on Rails 5.2.6.3 is not latest version but it should be easy to pull-up
to pkgsrc-2021Q4.

Changes are in devel/ruby-activestorage52 only.

Rails 5.2.6.3 (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]

(taca)