Description of problem:

createrepo can be installed without python-urlgrabber but won't work without it.

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

createrepo-0.4.4-2

How reproducible:

Always

Steps to Reproduce:
1. rpm -e python-urlgrabber
2. rpm -i createrepo
3. createrepo pathtorepo
  
Actual results:

It will complain about missing urlgrabber import

Expected results:

It should verify dependency on python-urlgrabber during installation.

Additional info:

It is possible to perform minimal Fedora install from where python-urlgrabber is
missing and install createrepo later. This is how I've got this bug.