Update TargetExtractor.py

fixed my image dimension issue  (refer to pull request ethz-asl#15)

Author: Chiasung

aslam_offline_calibration/kalibr/python/kalibr_common/TargetExtractor.py

@@ -18,6 +18,7 @@ def multicoreExtractionWrapper(detector, taskq, resultq, clearImages, noTransfor
         stamp = task[1]
         image = task[2]
 
+        image = image.reshape(filter(lambda dim: dim != 1, image.shape)) 
         if noTransformation:
             success, obs = detector.findTargetNoTransformation(stamp, np.array(image))
         else: