Mysql server crashes because unsafe statements warning is wrongly elevated to error,
which is set the error status of Diagnostics_area of the thread in THD::binlog_query().
Yet the caller believes that binary logging shouldn't touch the status, so it will
set the status also later by my_ok(), my_error() or my_message() seperately
according to the execution result of the statement or transaction.
But the status of Diagnostics_area of the thread is allowed to set only once.

Fixed to clear the error wrongly set by binary logging, but keep the warning message.