HPA kit for WE GBBRs - small update

After some grinding, I managed to improve the kit a bit, mainly making it easier to manufacture but also increase reliability.

[@NerveJascha]

Left a Sub for the apportunity to see an HPA conversion for the WE SCAR H one day!

[@joshyazg2120]

Same. Paitently waiting to see if he will ever return to selling them.

[@mikelondres3874]

What if the line goes through the side by just making a hole in the receiver? (So there is no need to mod the internals in order to fit that tube)