NoWildcardAcceptPredicate drop useless override of __init__

Follow-up 5182ff4293ee

pyramid.predicates.AcceptPredicate handle both single and multiple values now
https://github.com/Pylons/pyramid/blob/0c29cf2df41600d3906d521c72991c7686018b71/src/pyramid/predicates.py#L138

cubicweb_jsonschema/predicates.py

@@ -25,11 +25,6 @@ class NoWildcardAcceptPredicate(predicates.AcceptPredicate):
     See https://github.com/Pylons/pyramid/issues/1264.
     """
 
-    def __init__(self, val, config):
-        if not isinstance(val, (list, tuple)):
-            val = (val, )
-        super(NoWildcardAcceptPredicate, self).__init__(val, config)
-
     def __call__(self, context, request):
         request_accepts = [h for h in request.accept if h != '*/*']
         for accept_type in self.values: