Draw as Border pulls a default texture containing all icons in the engine when applied to a button

When changing The Draw as setting for a button widget to "Border" it automatically sets the image for the border to that of a sprite sheet that is used for all of the icons in the engine.

1. Open the Editor
2. Create a new widget blueprint
3. Drag a button in to the designer tab
4. Resize the button so that it is easy to see
5. Set the Draw as setting to "Border"
   Style > Normal > Draw as > border
6. Notice that the button now shows up as a sprite sheet full of all of the icons in the engine

Expected: The button becomes a border version of the default gray
Result: the button is given a new texture that looks like a sprite sheet