message: set plunger position to 'bottom' during pick-up-tip to avoid firmware bug
diff: @@ -996,6 +996,8 @@ class Pipette(Instrument):
  def _do():
  nonlocal location, presses
  + self.motor.move(self._get_plunger_position('bottom'))
  +
  if location:
  self.move_to(location, strategy='arc', enqueue=False)
  