If applied, this commit will change json request body from payload to…

… data.

src/main/java/dlt/client/tangle/hornet/model/LedgerWriter.java

@@ -123,7 +123,7 @@ public void createMessage(String index, String data) {
             connection.setDoOutput(true);
 
             String requestBody = String.format(
-                    "{\"index\": \"%s\",\"payload\": %s}",
+                    "{\"index\": \"%s\",\"data\": %s}",
                     index,
                     data
             );