remove redundant check in Constructor: null cannot be recursive
diff --git a/src/main/java/org/yaml/snakeyaml/constructor/Constructor.java b/src/main/java/org/yaml/snakeyaml/constructor/Constructor.java
index 82e31b0..77cfcf5 100644
--- a/src/main/java/org/yaml/snakeyaml/constructor/Constructor.java
+++ b/src/main/java/org/yaml/snakeyaml/constructor/Constructor.java
@@ -216,7 +216,7 @@
         if (!node.isTwoStepsConstruction()) {
             throw new YAMLException("Unexpected recursive structure. Node: " + node);
         }
-        if (Object.class.equals(node.getType()) || Tags.NULL.equals(node.getTag())) {
+        if (Object.class.equals(node.getType())) {
             super.callPostCreate(node, object);
         } else {
             switch (node.getNodeId()) {