do not check for default scopes

[morr]

Do not pass ::Doorkeeper.configuration.default_scopes in token.acceptable?.

This logic is completely broken when ::Doorkeeper.configuration.default_scopes != [].
default_scopes are scopes that applied to the token when application owner did not provide any desired scopes.
But when application DID provide desired scopes, then these scopes could not match with default_scopes and thus authentication fails.

And one more thing. devise-doorkeeper should not check scopes anyway because scopes are checked on controller level via doorkeeper_authorize! :scope_name directive.