[Nantes] Remove physical servers that have been shutdown

This merge request remove physical servers that have been shutdown and are not used anymore on Grid'5000/ABACA:

• srv.nantes
• srv-2.nantes
• ceph0.nantes
• ceph1.nantes
• ceph2.nantes
• ceph3.nantes

assigned to @pijacquo

requested review from @jlelaura

approved this merge request

added 3 commits

• 50148242...faf3558a - 2 commits from branch master
• 0f41eaa3 - [Nantes] Remove physical servers that have been shutdown

Compare with previous version

merged

mentioned in commit 07dd49b4