Bug revise of monkey patch without Rails gem

[kaidotdev]

such as rails-html-sanitizer gem uses Rails constant without rails gem
ref. https://github.com/rails/rails-html-sanitizer/blob/master/lib/rails/html/sanitizer.rb#L1

[jcarres-mdsol]

Good.
I think you need to:

• Create something like:

def running_inside_rails?
   defined?(Rails) && defined?(Rails.application)
end

• Use that method in the two lines you have modified
• Pass the tests
• Update minor version and changelog

[jcarres-mdsol]

I'm closing this, we are going to revisit this section of the code soon