Description of problem:
yum "group*" options do not work for cloned channels

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


How reproducible:
Always

Steps to Reproduce:
1. Create cloned channel
2. Subscribe system to the cloned channel
3. Run yum group{list,info,install}
  
Actual results:
No group action is executed.

Expected results:
Respective group action executed.

Additional info:
Yum looks for the comps.xml file to find group definitions, but cannot find it,
for whatever reason.