[pve-devel] Live storage migration v6

[Alexandre Derumier]

changelog:
  - check if the number of local disk generate to target host is equal
    to number of local disk on source host
  - do a tcp check on nbd port before starting mirroring
  - fix parsing of source disk format 
  - fix ipv6 bracket in qmp nbd start. (for nbd_uri we need bracket).
    Note that I don't have ipv6 for test

unchanged:
  - source disks removal after migration
  - skipcomplete logic in clone_disk