[vbox] Bootstrap for slave node failed. No more network devices

[Anastasia Palkina]

I reproduced this issue twice on ISO #307 and on ISO #327

1. Install master node
2. Power off one of 3 slave nodes and clone it 7 times
3. Start clone nodes
4. Installing of one of clone nodes has failed with error "No more network devices" (see screen)
5. If you restart this node, it install successfully

VERSION:
  feature_groups:
    - mirantis
  production: "docker"
  release: "8.0"
  api: "1.0"
  build_number: "327"
  build_id: "327"
  fuel-nailgun_sha: "ec25ae8df28e1f1d87da653c5aab2711dff729f6"
  python-fuelclient_sha: "7c7a756fb6a3d091851c060003a2965c67aa353d"
  fuel-agent_sha: "d354cbe61b055db848a15ce66fb7ae92178d2c0a"
  fuel-nailgun-agent_sha: "a33a58d378c117c0f509b0e7badc6f0910364154"
  astute_sha: "c56dfde2da034151a7e707b381c4cf9d213b4ba2"
  fuel-library_sha: "bcc3d042a47547f6ad826360a85ef21dcaf25882"
  fuel-ostf_sha: "b2ebf15a3530b5c7b57707acf8642c1c3ac71bd8"
  fuel-mirror_sha: "8100acb3a566358d0d4ecc66de32d39626263028"
  fuelmenu_sha: "2942a85796d37f09ba8c8c6d762d8813292cf0d4"
  shotgun_sha: "cacb93cbc28910ff0dc38f30a855efa9af50d8ce"
  network-checker_sha: "d443ef47abeda58d319bc8d33d5005dd09440a02"
  fuel-upgrade_sha: "718aa3d7021fee2970f0fa6791cf5188578cc516"
  fuelmain_sha: "3faa824728ce60734abe602ff3778976f8a16eed"

[Dmitry Pyzhov (dpyzhov)]

This bug seems to be related to high load on local machine caused by simultaneous run of big number of virtual machines. Setting priority to Medium. And it doesn't seem that we have a way to fix it.