Use Time.current converted to Date by the database DirectMessage today scope

Why:

* Database stores created_at as timestamp with the timezone, so when comparing DATE(created_at) to something we have to convert it to DATE as well with the postresql native function, but using Time.current instead of Date.current to take into account the user timezone

app/models/direct_message.rb

@@ -8,7 +8,7 @@ class DirectMessage < ActiveRecord::Base
   validates :receiver, presence: true
   validate  :max_per_day
 
-  scope :today, lambda { where('DATE(created_at) = ?', Date.current) }
+  scope :today, lambda { where('DATE(created_at) = DATE(?)', Time.current) }
 
   def max_per_day
     return if errors.any?