Fix the evacuate API without json-schema validation in 2.13
Fix the evacuate API without json-schema validation in 2.13

The evacuate API loses the json-schema validation in 2.13 since
the commit c01d16e81af6cd9453ffe7133bdc6a4c82e4f6d5. This patch
fixes it.

Change-Id: I7f221e3b924d91739ec9b24fd090410fb5fce55a
Closes-bug: #1683752

openstack/nova,rajalokan/nova,jianghuaw/nova,phenoxim/nova,openstack/nova,klmitch/nova,rajalokan/nova,phenoxim/nova,Juniper/nova,gooddata/openstack-nova,mahak/nova,Juniper/nova,mikalstill/nova,mahak/nova,rahulunair/nova,jianghuaw/nova,vmturbo/nova,vmturbo/nova,klmitch/nova,gooddata/openstack-nova,Juniper/nova,rahulunair/nova,jianghuaw/nova,openstack/nova,klmitch/nova,gooddata/openstack-nova,mikalstill/nova,mikalstill/nova,Juniper/nova,vmturbo/nova,jianghuaw/nova,mahak/nova,rajalokan/nova,rahulunair/nova,rajalokan/nova,klmitch/nova,gooddata/openstack-nova,vmturbo/nova