Set "modified" as default sort option in "Translate sentences"
Set "modified" as default sort option in "Translate sentences"

Ref. #1351

To keep the same order as how it was before the sort options were introduced.

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