Update check of libvirt(d) group

Current check assumes whitespaces on either side of group name.
This patch removes that assumption

Signed-off-by: Michael S. Pedersen <michaelx.pedersen@intel.com>
Change-Id: I4802420530be05831b8611b812c9866055cac714
Reviewed-on: https://gerrit.opnfv.org/gerrit/c/kuberef/+/71257
Tested-by: jenkins-ci <jenkins-opnfv-ci@opnfv.org>
Reviewed-by: Victor Morales <chipahuac@hotmail.com>
Reviewed-by: Georg Kunz <georg.kunz@ericsson.com>