fixed order of availalbe_operators of project_id filter

git-svn-id: https://dev.finn.de/svn/cockpit/branches/reporting_merge@1851 7926756e-e54e-46e6-9721-ed318f58905e

app/models/cost_query/filter/project_id.rb

@@ -1,7 +1,10 @@
 class CostQuery::Filter::ProjectId < CostQuery::Filter::Base
   db_field "entries.project_id"
   label :field_project
-  use "=_child_projects", "!_child_projects"
+
+  def self.available_operators
+    ["=", "!", "=_child_projects", "!_child_projects"].map { |s| s.to_operator }
+  end
 
   ##
   # Calculates the available values for this filter.