Fix ci deploy job error

Fix ci deploy job error

Fix issue:
https://build.opnfv.org/ci/view/clover/job/clover-daily-deploy-master/4/consoleFull
+ ssh -i /home/jenkins/opnfv/slave_root/workspace/clover-daily-deploy-master/work/container4nfv/src/vagrant/kubeadm_istio/.vagrant/machines/master/libvirt/private_key vagrant@192.168.121.117 rm -rf clover
Host key verification failed.

Change-Id: I73ea912ca6eb7ef823b1694b9fb090d809f158ee
Signed-off-by: QiLiang <liangqi1@huawei.com>