Assign a speedmasters Learn button to an Buttonexecutor

Speedmasters may only be assigned to faders. This workaround let you assign a Speedmaster Learn-button to the Executorbuttons

1. Create a dummy effect (an effect with some unused channels/attributes)
2. Link Effect to Speedgroup x
3. Assign Effect to executorbutton
4. Assign Learn to button of Effect

As the effect is linked to the speedgroup, learning the speed to the effect, will also learn speed to the speedgroup.