Implemented issue #722 - Do not log last_login in user history.

app/models/user.rb

@@ -63,6 +63,7 @@ class User < ApplicationModel
                                      :preferences
 
   history_attributes_ignored :password,
+                             :last_login,
                              :image,
                              :image_source,
                              :preferences

db/migrate/20170203000001_remove_last_login_from_history_722.rb

@@ -0,0 +1,13 @@
+class RemoveLastLoginFromHistory722 < ActiveRecord::Migration
+  def up
+
+    # return if it's a new setup
+    return if !Setting.find_by(name: 'system_init_done')
+
+    history_object = History.object_lookup('User')
+    return if !history_object
+    history_attribute = History.attribute_lookup('last_login')
+    return if !history_attribute
+    History.where(history_object_id: history_object.id, history_attribute_id: history_attribute.id).delete_all
+  end
+end