Prevent bottom silk dot

@poeschlr Please take a look at this. This code draws a bottom silk line with the same start and end points. It ends up placing a silk dot on the X axis under the lower F.SilkS horizontal line. There are no conditionals around this section of code so it runs for every single footprint using this script.

Why? I don't see why any gullwing parts need bottom silk. Am I missing the purpose of this?

I block commented to create the PR, but I can remove these few lines of code if it's not needed.