Play button cuts into dropdown corners

[roblourens]

The left corners of the debug viewlet dropdown are missing the border - maybe the play button is running into them. I see this in Light+ and Solarized Dark

[miguelsolorio]

FYI @isidorn, this was caused from the recent debug theming colors. I removed the bg color from the start button as it is already applied to the entire select dropdown.

[isidorn]

@misolori thanks for fixing it!