Termination rates - STRIP field is not accepted in double zero when termination rate is imported.

Steps to reproduce :

1. Login in admin
2. Go to carrier menu
3. Click on termination rate
4. Click on import button
5. Download sample file and verify strip field is not accepted in double zero
6. Verify prepend field is not accepted in double zero

Expected result :

  > STRIP field should be accepted double zero.

 > Prepend field should be accepted double zero.