re #305.
re #305.

In sentence_buttons.php, und -> unknown.

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