Wilson Step-Deck Fertilizer trailer FS 19

Update to my edit of the Wilson Stepdeck trailer
After being brought to my attention, the trailer was causing a massive lua error when combined with the sprayer craddle from Freedom Modding that would cause the game to freeze up when detaching the trailer with the cradle attached.List of changes:
• Fixed issue causing lua error when combined with the sprayer cradle and attempting to detach the trailer while the craddle is attached
• Changed category to Low Loaders
• Updated textures and shaders (Courtesy of AJ Bentley)