Update TopicTree fuzzing

fuzzing/TopicTree.cpp

@@ -54,7 +54,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
                 }
             } else if (data[4] == 'P') {
                 /* Publish */
-                topicTree.publish(lastString, lastString);
+                topicTree.publish(lastString, {lastString, lastString});
             } else if (data[4] == 'D') {
                 /* Drain */
                 topicTree.drain();