Add missing milestone ID

app/models/milestone.rb

@@ -16,9 +16,9 @@
 class Milestone < ActiveRecord::Base
   # Represents a "No Milestone" state used for filtering Issues and Merge
   # Requests that have no milestone assigned.
-  MilestoneStruct = Struct.new(:title, :name)
-  None = MilestoneStruct.new('No Milestone', 'No Milestone')
-  Any = MilestoneStruct.new('Any', '')
+  MilestoneStruct = Struct.new(:title, :name, :id)
+  None = MilestoneStruct.new('No Milestone', 'No Milestone', 0)
+  Any = MilestoneStruct.new('Any', '', -1)
 
   include InternalId
   include Sortable