Replace deprecated update_attributes with update.

https://rubyinrails.com/2019/04/09/rails-6-1-activerecord-deprecates-update-attributes-methods/

DEPRECATION WARNING: update_attributes! is deprecated and will be removed from Rails 6.1 (please, use update! instead)

app/models/note.rb

@@ -139,14 +139,7 @@ class Note < ApplicationRecord
 
   def merge_version
     prev = versions.last
-    prev.update_attributes(
-      :x => x,
-      :y => y,
-      :width => width,
-      :height => height,
-      :is_active => is_active,
-      :body => body
-    )
+    prev.update(x: x, y: y, width: width, height: height, is_active: is_active, body: body)
   end
 
   def merge_version?(updater_id)