Re-onboarding of an existing device is not working if the device type is not present

[dgarros]

Environment

• Python version: 3.7.7
• NetBox version: 2.8.8
• ntc-netbox-plugin-onboarding version: 1.2.0

Steps to Reproduce

1. Disable create_device_type_if_missing
2. Ensure the device type matching the device is not already present
3. Re-onboard an existing device

Expected Behavior

Since the device already exist and already have a device_type assigned, the re-onboarding should work as expected.

Observed Behavior

The re-onboarding is failing because the device_type is not present