SecureRandom.urlsafe_base64 doesn't have padding: false keyword argument

Actually it is regarded truthy as `padding = { padding: false }`.

https://docs.ruby-lang.org/en/2.7.0/Random/Formatter.html#method-i-urlsafe_base64

Author: kamipo

actionpack/lib/action_controller/metal/request_forgery_protection.rb

@@ -469,7 +469,7 @@ def normalize_action_path(action_path) # :doc:
 
       def generate_csrf_token # :nodoc:
         if urlsafe_csrf_tokens
-          SecureRandom.urlsafe_base64(AUTHENTICITY_TOKEN_LENGTH, padding: false)
+          SecureRandom.urlsafe_base64(AUTHENTICITY_TOKEN_LENGTH)
         else
           SecureRandom.base64(AUTHENTICITY_TOKEN_LENGTH)
         end