Don't catch exception from impedance measurement thread
Don't catch exception from impedance measurement thread

Was throwing cryptic error which was hard to track down.

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