never try to render the progressbar instead of the table. fixes no render on GET

app/controllers/cost_reports_controller.rb

@@ -153,6 +153,13 @@ class CostReportsController < ApplicationController
   #   {:rows => (rows || []), :columns => (columns || [])}
   # end
 
+  ##
+  # @Override
+  # We cannot show a progressbar in Redmine, due to Prototype being less than 1.7
+  def no_progress?
+    true
+  end
+
   ##
   # Set a default query to cut down initial load time
   def default_filter_parameters