Make sure RPM passes DB_CREATE to Berkeley-DB

     Change: bdb-allow-zero-sized-files
     Purpose: Make sure RPM passes DB_CREATE to Berkeley-DB also
                     if file exists, but is (still) zero-sized.
     Reason: In OpenPKG all database files are pre-created
                     to fixate permissions.
     Hint: This might be obsolete soon as we now create real
                     BDB files instead of empty files.