Don't crash when I create new PipeTypes

I am using reflection to "hack in" new PipeTypes for myself.
(Yes, that IS possible, but very "aggressive")

Don't cause an ArrayIndexOutOfBounds exception when I do that.
(at least when rendering, just don't place a gate on my pipes)

This is also another step towards
the ability to create new PipeTypes.
Forgot the import

Add the pipetype import
Merge pull request #1784 from undergroundminer3/6.0.x

Don't crash when I create new PipeTypes
Merge branch '6.0.x' into 6.1.x