[Comment Modification] Modify the training sample number from 20 to 19 in the comments

bob/ip/binseg/data/drhagis/__init__.py

@@ -20,7 +20,7 @@ The images resolutions (height x width) are:
 
 * Protocol ``default``:
 
-  * Training samples: 20 (including labels and masks)
+  * Training samples: 19 (including labels and masks)
   * Test samples: 20 (including labels and masks)