Fixed typo in obj stig variable name. (#85)

src/instamatic/TEMController/simu_microscope.py

@@ -500,7 +500,7 @@ def setIntermediateLensStigmator(self, x: int, y: int):
  self.intermediatelensstigmator_y = y
 
  def getObjectiveLensStigmator(self) -> Tuple[int, int]:
- return self.objectivelensstigmator_x, self.objectivelensstigmatir_y
+ return self.objectivelensstigmator_x, self.objectivelensstigmator_y
 
  def setObjectiveLensStigmator(self, x: int, y: int):
  self.objectivelensstigmator_x = x