Fix, Use devise_will_save_change_to_email? method for email change detection (#1654)

* fix: Update method names to devise_will_save_change_to_email?

* fix: Remove email_changed? method

Author: hnegishi

app/models/devise_token_auth/concerns/confirmable_support.rb

@@ -3,7 +3,7 @@ module DeviseTokenAuth::Concerns::ConfirmableSupport
 
   included do
     # Override standard devise `postpone_email_change?` method
-    # for not to use `will_save_change_to_email?` & `email_changed?` methods.
+    # for not to use `devise_will_save_change_to_email?` methods.
     def postpone_email_change?
       postpone = self.class.reconfirmable &&
         email_value_in_database != email &&

app/models/devise_token_auth/concerns/user.rb

@@ -41,8 +41,7 @@ def self.tokens_match?(token_hash, token)
 
     # don't use default devise email validation
     def email_required?; false; end
-    def email_changed?; false; end
-    def will_save_change_to_email?; false; end
+    def devise_will_save_change_to_email?; false; end
 
     if DeviseTokenAuth.send_confirmation_email && devise_modules.include?(:confirmable)
       include DeviseTokenAuth::Concerns::ConfirmableSupport