If ur neighbor or his driver or insurance company is paying to change it then definitely change the light with an original one. But if its onto ur pocket then live with it as it is not a big deal, a small crack, nothing chipped off. only ur eye is noticing it again and again.
I also had a cracked left back light and i didn't changed it. A few months later another motorcycle handle chipped off whole the light glass and then i got it changed. samajh to aap gayay hongay.
Sleep over it. Let it go. be happy.
But if u can't, just get the back lights smoked in Rs 500-800. No crack will remain noticeable.