The delete coordinate keybinding is broken if displayControlsDefault: false

Nobody has claimed this yet.

**mapbox-gl-js**: 0.47.0
**mapbox-gl-draw**: 1.0.9

var draw = new MapboxDraw({
displayControlsDefault: false,
keybindings: true,
});

draw.changeMode('draw_polygon');

#### Steps: ####
1) Draw a polygon with your mouse
2) Click one of the polygon's coordinates and select it
3) Hit delete on your keyboard.

#### Expected: ####
The coordinate deletes and the polygon changes shape.

#### Actual: ####
The coordinate only deletes if `displayControlsDefault: true`.

#### Demo: ####

Try switching `bugActive`:

https://jsbin.com/gidotifaxa/1/edit?html,output

Reproduce the behavior using the Mapbox GL Draw 1.0.9 configuration in the issue and the linked JSBin, with displayControlsDefault set to false and keybindings enabled. Start at the draw.changeMode('draw_polygon') entry point and trace how the delete key is registered and handled; done means deleting a selected coordinate changes the polygon in both control-display configurations.

Written by the indexing model from the issue text.