Error configuring Volume quotas.

[Olga Klochkova]

When configuring Default Quotas in System->Defaults->Update fields
- total size of volumes and snapshots
- volume snapshots
- volumes
are empty by default.
After entering some values in those fields and trying to save them error message appears: " Unable to retrieve volume limit information".
Quotas are not saved which could be checked by refreshing the page.

The same issue appears when editing Project quotas in Identity->Projects->Manage Members->Quota

VERSION:
  feature_groups:
    - mirantis
  production: "docker"
  release: "8.0"
  api: "1.0"
  build_number: "307"
  build_id: "307"
  fuel-nailgun_sha: "26c78e1c2913b8ca194126ca38161ff9593daef4"
  python-fuelclient_sha: "6810231ec6d333fc10f7020f9bdf5122e05e998a"
  fuel-agent_sha: "f4c22a341ce8a98cc9151bd928f1d97071288b3c"
  fuel-nailgun-agent_sha: "a33a58d378c117c0f509b0e7badc6f0910364154"
  astute_sha: "c56dfde2da034151a7e707b381c4cf9d213b4ba2"
  fuel-library_sha: "03558ce6627a5adb417b1f6bbe1c0b3a853e8d6b"
  fuel-ostf_sha: "9910a4726cbd038c257582b429527e40c4c3cb20"
  fuel-mirror_sha: "5d986722c7e911d1dd44800f2721bdbfcb7f3282"
  fuelmenu_sha: "5abc3c8fea8e578cf9250f40acf9df98adb214a3"
  shotgun_sha: "cacb93cbc28910ff0dc38f30a855efa9af50d8ce"
  network-checker_sha: "d443ef47abeda58d319bc8d33d5005dd09440a02"
  fuel-upgrade_sha: "718aa3d7021fee2970f0fa6791cf5188578cc516"
  fuelmain_sha: "713b2d7421f1ee660d17e406668f74550f96e18a"