Fix format string placeholder in strings-bn
Fix format string placeholder in strings-bn

These are incorrect in the translated strings and are causing a failure
in the translation tests.

Change-Id: I6d6474f76a897c1349e17339def5feeb245c7234

dbrant/apps-android-wikipedia,dbrant/apps-android-wikipedia,wikimedia/apps-android-wikipedia,dbrant/apps-android-wikipedia,wikimedia/apps-android-wikipedia,dbrant/apps-android-wikipedia,dbrant/apps-android-wikipedia,wikimedia/apps-android-wikipedia,wikimedia/apps-android-wikipedia