Fix HAFAS->similar_stops_p

	if ( $service and exists $hafas_instance{$service}{stopfinder} ) {

		$opt{user_agent} //= $self->{ua};

		$opt{promise}    //= $self->{promise};

		return Travel::Status::DE::HAFAS::StopFinder->new_p(

			url            => $hafas_instance{$service}{stopfinder},

			input          => $self->{station},

			ua             => $opt{user_agent},

			user_agent     => $opt{user_agent},

			developer_mode => $self->{developer_mode},

			promise        => $opt{promise},

		);