No need to nodoc private method

Author: amatsuda

actionmailer/lib/action_mailer/base.rb

@@ -568,7 +568,7 @@ def method_missing(method_name, *args) # :nodoc:
 
     private
 
-      def respond_to_missing?(method, include_all = false) #:nodoc:
+      def respond_to_missing?(method, include_all = false)
         action_methods.include?(method.to_s)
       end
     end