tests: Fix manual installation testcase on RHEV-H

Previosly some testcases relied on the presence of the "oVirt Node"
keyword, now the expression "oVirt Node|RHEV Hypervisor" is used, so the
same testcase works on RHEV-H.

Change-Id: I854f6f20e55040d23d098da799fae58490d00397
Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>