Relax replace_disks_all meaning for drbd8
Relax replace_disks_all meaning for drbd8

In order to make the replace secondary action to be done via the same
opcode parameters for both remote_raid1 and drbd, we must allow the
LUReplaceDisks to change replace_disks_all for drbd with non-empty
remote_node into replace_disks_sec.

This fixes gnt-node evacuate and also allows gnt-instace replace-disks
to have the same syntax for both remote_raid1 and drbd (when replacing
the secondary).

Reviewed-by: ultrotter


leshchevds/ganeti,apyrgio/ganeti,mbakke/ganeti,grnet/snf-ganeti,leshchevds/ganeti,dimara/ganeti,onponomarev/ganeti,yiannist/ganeti,bitemyapp/ganeti,ganeti/ganeti,mbakke/ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,dimara/ganeti,leshchevds/ganeti,apyrgio/snf-ganeti,grnet/snf-ganeti,andir/ganeti,mbakke/ganeti,ganeti/ganeti,andir/ganeti,andir/ganeti,yiannist/ganeti,apyrgio/ganeti,ganeti/ganeti,onponomarev/ganeti,bitemyapp/ganeti,apyrgio/snf-ganeti,ganeti-github-testing/ganeti-test-1