Description of problem:
When importing a VM from external provider and trying to switch to the VM disks tab a UI exception is thrown

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


How reproducible:


Steps to Reproduce:
1. In the VM tab click on "Import"
2. In the import popup select KVM (or any external provider for that matter) and fill in the connection details, select a VM to import and click "Next"
3. In the VM import data page click on the "Disks" sub tab

Actual results:
A UI exception is thrown

Expected results:
No exception should be thrown

Additional info: