Make the title of foreign file format warning translatable
Make the title of foreign file format warning translatable

Also, change the contained text slightly.
Thanks to William Gathoye for noticing and producing a first patch

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core