address #630; set default lang level to 0
address #630; set default lang level to 0

Set the default language (skill) level to 0. After this, we can change
the existing null values for this field to 0 in the db.

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