Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1634760

Description of problem:
Running 'hammer host create ...' without --interface specification leads to error in $SUBJ

I tried it with Sat 6.3 and didn't reproduce it (got a nice message "Could not create the host: Could not find virtual machine network interface matching 192.168.1.116") => seems like regression

Version-Release number of selected component (if applicable):
Reproduced on Sat 6.4 snap 24

How reproducible:
Deterministic

Steps to Reproduce:
1. Run 'hammer host create' command without specifying --interface parameter

Actual results:
[DEBUG 2018-10-01T16:19:57 Exception] Using exception handler HammerCLIForeman::ExceptionHandler#handle_unprocessable_entity
[ERROR 2018-10-01T16:19:57 Exception] Failed to create a compute rhev4 (RHV) instance fish.example.com: Ovirt client returned an error: undefined method `href' for nil:NilClass

Could not create the host:
Failed to create a compute rhev4 (RHV) instance fish.example.com: Ovirt client returned an error: undefined method `href' for nil:NilClass

Expected results:
Host created successfully

Additional info:
Traceback attached