Invalid tunnel destination for NodeID : null

Happens occasionally when running GBPSFC symm/asymm demo.

PolicyEnforcer cannot read next-hop destination (see log in the attachment).

REST data are sent to ODL one by one. Some of the processes which were triggered by data change event may take so long, that they don't finish before different process is triggered. In this case rendered-service-path had not been created by SFC plugin before PolicyEnforcer was looking it.