Fix missing versioned notification sample
Fix missing versioned notification sample

Add the 'instance-interface_attach-error' notification sample
to the nova document.

Change-Id: Ife45fd30fd723675b45c7170e02358ab352e05e0
CLoses-Bug: #1728884

rahulunair/nova,openstack/nova,mikalstill/nova,mikalstill/nova,gooddata/openstack-nova,gooddata/openstack-nova,mikalstill/nova,gooddata/openstack-nova,klmitch/nova,klmitch/nova,mahak/nova,mahak/nova,rahulunair/nova,rahulunair/nova,phenoxim/nova,gooddata/openstack-nova,mahak/nova,phenoxim/nova,openstack/nova,klmitch/nova,klmitch/nova,openstack/nova