Merge remote-tracking branch 'origin/dev_1.5.0_OneHotAttribute' into dev_1.5.0_OneHotAttribute

# Conflicts:
#	art/attacks/attack.py

Author: abigailgold

art/attacks/attack.py

@@ -321,6 +321,7 @@ def __init__(self, estimator, attack_feature: Union[int, slice] = 0):
         """
         :param estimator: A trained estimator targeted for inference attack.
         :type estimator: :class:`.art.estimators.estimator.BaseEstimator`
+        :param attack_feature: The index of the feature to be attacked.
         """
         super().__init__(estimator)
         self.attack_feature = attack_feature
@@ -345,10 +346,6 @@ def set_params(self, **kwargs) -> None:
         super().set_params(**kwargs)
         self._check_params()
 
-    def _check_params(self) -> None:
-        if self.attack_feature < 0:
-            raise ValueError("Attack feature must be positive.")
-
 
 class ReconstructionAttack(Attack):
     """