cs: Enable risky rule is_null.

src/Bundle/ChillMainBundle/Validation/Validator/RoleScopeScopePresence.php

@@ -69,7 +69,7 @@ class RoleScopeScopePresence extends ConstraintValidator
         } elseif // if the scope should be null
             (
                 in_array($value->getRole(), $this->roleProvider->getRolesWithoutScopes())
-                && !is_null($value->getScope())
+                && null !== $value->getScope()
             ) {
             $this->context->buildViolation($constraint->messageNullRequired)
                 ->setParameter('%role%', $this->translator->trans($value->getRole()))