Add label landb_sync_set
This label is used with the landb-sync utility to set automatically the landb-set property on the nodes that are configured as role=ingress
Closes: #6 (closed) Signed-off-by: Diogo Guerra diogo.filipe.tomas.guerra@cern.ch Change-Id: Id6e01d0a7d90d57106a90bb818cabc7197d823c4