Don't throw exception when there are no serial devices connected
Don't throw exception when there are no serial devices connected

wheeler-microfluidics/dmf-control-board-firmware,wheeler-microfluidics/dmf-control-board-firmware,wheeler-microfluidics/dmf-control-board-firmware,wheeler-microfluidics/dmf-control-board-firmware,wheeler-microfluidics/dmf_control_board_plugin