Fix missed memcpy update

Everything should be in terms of kNodeCopyBegin and kNodeCopySize now

ConflictSet.cpp

@@ -1466,9 +1466,8 @@ template <bool kBegin>
 
         *self = newNode<Node4>();
 
-        memcpy((char *)*self + sizeof(Node::type),
-               (char *)old + sizeof(Node::type),
-               sizeof(Node) - sizeof(Node::type));
+        memcpy((char *)*self + kNodeCopyBegin, (char *)old + kNodeCopyBegin,
+               kNodeCopySize);
         (*self)->partialKeyLen = partialKeyIndex;
         (*self)->entryPresent = false;
         (*self)->numChildren = 0;