remove MTU on all network equipments bug #9627

data/grid5000/sites/grenoble/network_equipments/gw.json

...00/sites/luxembourg/network_equipments/gw-luxembourg.json

data/grid5000/sites/luxembourg/network_equipments/mxl1.json

data/grid5000/sites/luxembourg/network_equipments/mxl2.json

...sites/luxembourg/network_equipments/ul-grid5000-sw02.json

data/grid5000/sites/lyon/network_equipments/force10.json

data/grid5000/sites/lyon/network_equipments/gw-lyon.json

data/grid5000/sites/nancy/network_equipments/gw-nancy.json

data/grid5000/sites/nancy/network_equipments/sgraphene1.json

data/grid5000/sites/nancy/network_equipments/sgraphene2.json

data/grid5000/sites/nancy/network_equipments/sgraphene3.json

data/grid5000/sites/nancy/network_equipments/sgraphene4.json

.../grid5000/sites/nancy/network_equipments/sgravillon1.json

data/grid5000/sites/nancy/network_equipments/sgrcinq.json

data/grid5000/sites/nancy/network_equipments/sgriffon1.json

data/grid5000/sites/nancy/network_equipments/sgrisou1.json

data/grid5000/sites/nancy/network_equipments/sgrvingt.json

...id5000/sites/nantes/network_equipments/ecotype-prod1.json

...id5000/sites/nantes/network_equipments/ecotype-prod2.json

data/grid5000/sites/nantes/network_equipments/gw-nantes.json