FIB table rules are not created when DPNTEPInfo is not available

when the first vm is created it trigger the creation of tunnels between compute nodes.
there are 2 models which are triggered by creation of vm port (InterfaceState):
1) vrfEntry creation
2) transport zone auto creation

the first model also depends on the existence of DPN-TEP which created by the second model. this can lead to a race when we handle the second model before the first one was fully handled. in this case vrfEntry will not be created and from now on nothing will re-trigger it.

in the log we see the error "NextHop for interface <name of interface> is null"