config-errhdl: Handle NoIdError from dbe_read.
config-errhdl: Handle NoIdError from dbe_read.

This commit is in prepartion for a follow-on to contrail-controller
where dbe_read will raise NoIdError and have caller decide on course
of action.

Partial-Bug: #1452835

Change-Id: Ib146e5fa00f09b3fc330bd793ddb0bb87d46d94b

vpramo/contrail-generateDS,varunarya10/contrail-generateDS,JioCloud/contrail-generateDS,varunarya10/contrail-generateDS,varunarya10/contrail-generateDS,JioCloud/contrail-generateDS,vpramo/contrail-generateDS,JioCloud/contrail-generateDS,vpramo/contrail-generateDS,vpramo/contrail-generateDS,JioCloud/contrail-generateDS,JioCloud/contrail-generateDS,varunarya10/contrail-generateDS,vpramo/contrail-generateDS,varunarya10/contrail-generateDS