Description of problem:
Cannot filter report when custom attributes are used in the condition from expression editor and such attributes are not used in selected fields.

Version-Release number of selected component (if applicable):
5.7

How reproducible:


Steps to Reproduce:
1. Add to any Vm (let assume with name test_vm) custom attribute 'test' with value 'vm'.
2. Create report based on Virtual Machines and add some column EXPECT TO column 'Custom Attribute: test'
3. go to filter tab and create the condition: 
Virtual Machine: Custom Attribute: Name = 'vm'.
4. Save and queue report, see results.

Actual results:
No vms are listed.

Expected results:
Vm with name test_vm is listed.

Additional info: