[nancy] mbi - remove mbi from api

data/grid5000/sites/nancy/clusters/mbi/mbi.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-1.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-10.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-11.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-12.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-13.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-14.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-15.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-16.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-17.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-18.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-19.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-2.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-20.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-21.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-22.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-23.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-24.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-25.json

data/grid5000/sites/nancy/clusters/mbi/nodes/mbi-26.json