syncVlansFromTables() fix: When removing a stale vlan, need to see if there are any trunked ports in that vlan, and remove them first, before doing the removeVlan().
syncVlansFromTables() fix: When removing a stale vlan, need to see if
there are any trunked ports in that vlan, and remove them first,
before doing the removeVlan().

nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome