Fix provision_encap.py to be able to set the Keystone tenant

Change-Id: I7648dc3c3da8a33fd602096f831653de7c7bdf84
Signed-off-by: Édouard Thuleau <edouard.thuleau@cloudwatt.com>
Merge "Fix provision_encap.py to be able to set the Keystone tenant"