* sensor: CLI "sub" and "unsub" commands

examples/simple_sensor/main.cpp

@@ -137,7 +137,7 @@ void loop() {
   if (len > 0 && command[len - 1] == '\r') {  // received complete line
     command[len - 1] = 0;  // replace newline with C string null terminator
     char reply[160];
-    the_mesh.handleCommand(0, command, reply);  // NOTE: there is no sender_timestamp via serial!
+    the_mesh.handleCommand(NULL, 0, command, reply);  // NOTE: there is no sender_timestamp via serial!
     if (reply[0]) {
       Serial.print("  -> "); Serial.println(reply);
     }