Removed transcription const definition from Sentence model.
Removed transcription const definition from Sentence model.

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