re #308.
re #308.

Added check to not add a link when a sentence doesn't exist.

Tatoeba/tatoeba2,Tatoeba/tatoeba2,shashank19gaurav/tatoeba2,Tatoeba/tatoeba2,Tatoeba/tatoeba2,Tatoeba/tatoeba2,shashank19gaurav/tatoeba2,shashank19gaurav/tatoeba2,shashank19gaurav/tatoeba2