LED Strip diffuser thinner top

This is a remix of the [LED Strip mounting profile](https://www.thingiverse.com/thing:2533803) by [HansVaa](https://www.thingiverse.com/HansVaa).

The original top part has a thickness of approximately 1 mm. I changed this to 0.4 mm as it looks a bit better when printed with white PLA. Printing with 1mm made white light a bit yellow-ish

Further I made is a bit shorter (200mm) so I can print it without turning it on my plate