Database <str> is already at the current structure level.

  Explanation:  The convert operation cannot be committed.  Either
  the  convert operation was already committed or the database was
  created using the current version of Oracle Rdb.

  User Action:  Use the RMU Show Version command  to  verify  that
  the  correct  version  of  RMU is executing.  Use the RMU Verify
  command to determine if the database has already been converted.