Message about failed network verification not disappears even after deleting the cause of fail

[Anastasia Palkina]

1. Create new environment by default
2. Add 1 controller
3. Open "Networks" tab
4. Click on "Connectivity Check" segment
5. Click "Verify Networks" button
6. Verification has failed because only 1 node in environment. Red message presented
7. Open "Dashboard" tab
8. Click "Cancel Changes" button. There are no nodes in environment now
9. Open "Networks" tab

Actual result: red error message still presents. Refresh page - red error message presents

Expected result: no error message

Logs are here: https://drive.google.com/a/mirantis.com/file/d/0B6SjzarTGFxacmp6akU4WGhMU1k/view?usp=sharing

VERSION:
  feature_groups:
    - mirantis
  production: "docker"
  release: "8.0"
  openstack_version: "2015.1.0-8.0"
  api: "1.0"
  build_number: "197"
  build_id: "197"
  fuel-nailgun_sha: "8d6ef41f1bef84378a61ee98b46aeb2b925fd10f"
  python-fuelclient_sha: "e685d68c1c0d0fa0491a250f07d9c3a8d0f9608c"
  fuel-agent_sha: "1d98edb0468aa70b9b3a43b8422804e9095e7d9d"
  fuel-nailgun-agent_sha: "b56f832abc18aee9a8c603fd6cc2055c5f4287bc"
  astute_sha: "c8400f51b0b92254da206de55ef89d17fdf35393"
  fuel-library_sha: "33c0fa3aada734dc9e6f315197ce0e4a16f5987c"
  fuel-ostf_sha: "11afd5743a12b1006317d3ca7000d1ede77bdae2"
  fuel-createmirror_sha: "994fed9b1ed889718b61a59733275c08c2dd4c64"
  fuelmenu_sha: "d12061b1aee82f81b3d074de74ea27a6e962a686"
  shotgun_sha: "c377d163519f6d10b69a654019d6086ba5f14edc"
  network-checker_sha: "2c62cd52655ea6456ff6294fd63f18d6ea54fe38"
  fuel-upgrade_sha: "1e894e26d4e1423a9b0d66abd6a79505f4175ff6"
  fuelmain_sha: "22fe551f5525d11a1854fd87dbc8c77fae8fec08"