fix build error in osx: ambiguous conversion for functional-style cast from 'int' to 'DbEnv
fix build error in osx: ambiguous conversion for functional-style cast from 'int' to 'DbEnv

exclfork/ExclusiveCoin,exclfork/ExclusiveCoin,exclfork/ExclusiveCoin,exclfork/ExclusiveCoin,exclfork/ExclusiveCoin,exclfork/ExclusiveCoin