TRAP! Improved Retainer Clips

Slightly improved retaining clip for [TRAP!](https://www.thingiverse.com/thing:127721). It's amazing how strong the pla springs are on the TRAP! design. I had a small issue where when the trap went off the clips would fly off and get lost. With this version I haven't had these issues. Once printed they just push over the rounded ends of the u-bolts.