JS: Update a reference to AdditionalSanitizerGuardNode

Unlike most other references to this class, we're not subclassing it here, we're
just trying to reuse some standard barrier guards but with a different flow state.

Author: asgerf

javascript/ql/src/Security/CWE-915/PrototypePollutingFunction.ql

@@ -465,7 +465,7 @@ class AllowListInclusionGuard extends BarrierGuard {
   }
 
   override predicate blocksExpr(boolean outcome, Expr e, DataFlow::FlowLabel lbl) {
-    this.(TaintTracking::AdditionalSanitizerGuardNode).sanitizes(outcome, e) and
+    this.(TaintTracking::AdditionalBarrierGuard).blocksExpr(outcome, e) and
     lbl instanceof UnsafePropLabel
   }
 }