Quality patch for Racetrack!

Quick patch update for Racetrack assets! 

Shoutout to @Vancete in our Discord community for bringing this up and making this asset pack better for everyone!

Changelog:

• Added missing: ''StartLight1'' in exports and .blend file
• Fixed ''Racetrack1_Default_Fork_Curb_Right'' and ''Racetrack1_RedGray_PitLane_Boxes'' models