Update ValueError comment

Author: beat-buesser

art/metrics/verification_decisions_trees.py

@@ -204,7 +204,10 @@ def verify(
         :return: A tuple of the average robustness bound and the verification error at `eps`.
         """
         if np.min(x) < 0 or np.max(x) > 1:
-            raise ValueError("There are features not in the range [0,1].")
+        raise ValueError(
+            "There are features not in the range [0, 1]. The current implementation only supports normalized input"
+            "valuesfeatures in range [0 1]."
+        )
 
         self.x: np.ndarray = x
         self.y: np.ndarray = check_and_transform_label_format(