fixed a typo

src/toolbox_scs/detectors/hrixs.py

@@ -277,7 +277,7 @@ def _new_centroid(image, threshold=THRESHOLD, std_threshold=3.5, curvature=(CURV
     return res
 
 def _new_centroid_double(image, threshold=THRESHOLD, std_threshold=3.5, 
-        double_thresh=1.5, curvature=(CURVE_A, CURVE_B)):
+        dbl_threshold=1.5, curvature=(CURVE_A, CURVE_B)):
     """
     A photon is supposed to have hit the detector if the intensity within a
     2-by-2 square exceeds a threshold. In this case the position of the photon