fixed constraint checking logic

bilby/core/prior/dict.py

@@ -407,7 +407,7 @@ class PriorDict(dict):
         outsample = self.conversion_function(sample)
         # Check if there is a constraint in sample/outsample
         if (np.any(isinstance([self[key] for key in sample.keys()], Constraint)) or
-                np.any(isinstance([self[key] for key in outsample.keys()]))):
+                np.any(isinstance([self[key] for key in outsample.keys()], Constraint))):
             # If constraint exists in keys, caclulate the cached normalization constant
             ratio = self.normalize_constraint_factor(sample.keys())