Remove database creation code + fix isActual() when database is empty

Some code fixes to allow the use of this adapter with my application.

Main problem : the adapter throws an exception in all case if the database doesn't exist. My solution was to remove all the database creation code. It will return now an error in callback during the database USE query. The database must be created externally (like the pgsql adapter).

Second problem : the function isActual() returns an error when any table is missing. The fix is to return no error and actual=false to allow autoupdate() to create all tables.