[nancy] add some warranty for networks equipements

input/grid5000/sites/nancy/networks/gw-nancy.yaml

input/grid5000/sites/nancy/networks/sgraphene1.yaml

input/grid5000/sites/nancy/networks/sgraphene2.yaml

input/grid5000/sites/nancy/networks/sgraphene3.yaml

input/grid5000/sites/nancy/networks/sgraphene4.yaml

input/grid5000/sites/nancy/networks/sgravillon1.yaml

input/grid5000/sites/nancy/networks/sgriffon1.yaml

input/grid5000/sites/nancy/networks/stalc2.yaml

input/grid5000/sites/nancy/networks/stalc3.yaml

input/grid5000/sites/nancy/networks/stalc4.yaml