"Please select" for blank value in Subnet dropdown is misleading
|Assigned To:||Lukas Zapletal|
|Found in release:||Pull request:||https://github.com/theforeman/foreman/pull/4536|
|Velocity based estimate||-|
It is possible to create hosts without subnets, therefore "Please select" label is misleading, let's change it to "Not set" or similar.