Partitioning settings goes to defaults after resetting env.

[Leontii Istomin]

If you reset environment disk settings of nodes goes to defaults.

Steps to reproduce:
1) Configure an Fuel environment
2) Change default disk settings of nodes
3) Click "deploy changes" button.
4) Wait until cluster became deployed/error state
5) Click "reset" button on the "actions" tab.
6) Wait the message that the env was successfully reset.
7) Check disk settings which you changed on 2d step.

expected: partitioning should be configured as we set it on 2d step
Actual behaviour: You'll see default configuration.