'NoneType' object has no attribute 'lower'

[thorstenhornung1]

Dear Hugo,

thanks for fixing the previous issue: #147
Unfortunately now I get a different error

Logger: custom_components.stateful_scenes.config_flow
Quelle: custom_components/stateful_scenes/config_flow.py:96
Integration: Stateful Scenes (Dokumentation, Probleme)
Erstmals aufgetreten: 07:45:04 (1 Vorkommnisse)
Zuletzt protokolliert: 07:45:04

'NoneType' object has no attribute 'lower'

Thank you so much in advance for looking into this,
Thorsten