Description of problem: Discovery provisioning fails with undefined method `assign_single_environment' for nil:NilClass

Version-Release number of selected component (if applicable): 6.14.0 snap 9

How reproducible: Always

Steps to Reproduce:
1. Set up the discovery plugin and try to provision a host.
2.
3.

Actual results: Provisioning fails

Expected results: Provisioning should work

Additional info: The host get's discovered successfully but cannot provision.