Fix connector parameter requirements
Fix connector parameter requirements

the database parameter which was required when no dsn was defined is
an odbc attributes which is optional for some drivers

splashblot/dronedb,CartoDB/cartodb,CartoDB/cartodb,splashblot/dronedb,CartoDB/cartodb,CartoDB/cartodb,splashblot/dronedb,CartoDB/cartodb,splashblot/dronedb,splashblot/dronedb