[Bug] It's impossible to create a new fixture and add lamp controls

To define the lamp controls for a device:

1. With the fixture selected, press {Lamp Ctrls}. The lamp control display will open.

1. Press {New} to add as many lamp control options as needed.

For currently existing fixtures that already have lamp control parameters, it works as expected.

For any fixtures that don't already have lamp control parameters, nothing happens.