when using running order, all input forms result in an error if the active debate has not been saved at least once

[wolfskaempf]

1. Create Running Order Session
2. Create Committees
3. Try to open the submit form of a commitee

[wolfskaempf]

See https://sentry.io/tom-wolfskampf/ga-statistics/issues/263894739/

[wolfskaempf]

I guess the general fix could be to set the first committee, that is created to the active debate. It would still leave an edge case if it is deleted later, but that should be possible to take care of within the model deletion handler.