Fix Python code, for the tutorial_laplace_operator, to get the same result…

Fix Python code, for the tutorial_laplace_operator, to get the same result between the Cpp, Java and Python

samples/python/tutorial_code/ImgTrans/LaPlace/laplace_demo.py

@@ -40,7 +40,7 @@ def main(argv):
 
     # [laplacian]
     # Apply Laplace function
-    dst = cv.Laplacian(src_gray, ddepth, kernel_size)
+    dst = cv.Laplacian(src_gray, ddepth, ksize=kernel_size)
     # [laplacian]
 
     # [convert]