Closes-Bug: #1587761 Handle null exception while accessing VN data.
Closes-Bug: #1587761
Handle null exception while accessing VN data.

Change-Id: Id4ee69575bcfbdc0ffbd71e252c3546e6d55b0de

vishnuvv/contrail-web-controller,skizhak/contrail-web-controller,biswajit-mandal/contrail-web-controller,sbavanasi/contrail-web-controller,biswajit-mandal/contrail-web-controller,vishnuvv/contrail-web-controller,biswajit-mandal/contrail-web-controller,sbavanasi/contrail-web-controller,sbavanasi/contrail-web-controller,vishnuvv/contrail-web-controller