Update example to use latest API.

Signed-off-by: Santiago Pericas-Geertsen <[email protected]>

Author: spericas

examples/webserver/jsonrpc/src/main/java/io/helidon/examples/webserver/jsonrpc/JsonRpcMain.java

@@ -63,8 +63,8 @@ static class MachineService implements JsonRpcService {
         public void routing(JsonRpcRules rules) {
             rules.register("/machine",
                            JsonRpcHandlers.builder()
-                                   .putMethod("start", this::start)
-                                   .putMethod("stop", this::stop)
+                                   .method("start", this::start)
+                                   .method("stop", this::stop)
                                    .build());
         }