Comment 4 for bug 1437105

Reviewed: https://review.opencontrail.org/8837
Committed: http://github.org/Juniper/contrail-controller/commit/c6b3730099345a4870ac5a06a3c1bb448d224b7a
Submitter: Zuul
Branch: R2.1

commit c6b3730099345a4870ac5a06a3c1bb448d224b7a
Author: Praveen K V <email address hidden>
Date: Thu Apr 2 14:59:43 2015 +0530

Handle VLAN property not set in logical-interface

We do not allow modificaiton of vlan-tag in logical-interface. But, in
IFMap messages its possible that VLAN-Tag property is not set. In
such case, we were setting vlan-tag to 0 and then change the value later
when property is received.

Modified agent code to ignore IFMap messages when vlan-tag property is
not set.

Change-Id: I7447a757c7a15367ffb75e881e266379b26c1abc
Fixes-bug: #1437105