Implementation of Unsuback (unless MqttClient disconnects)

src/TinyMqtt.cpp

@@ -498,6 +498,11 @@ if (mesg->type() != MqttMessage::Type::PingReq && mesg->type() != MqttMessage::T
 			}
 			break;
 
+		case MqttMessage::Type::UnSuback:
+			if (!mqtt_connected) break;
+			bclose = false;
+			break;
+
 		case MqttMessage::Type::Publish:
 			if (mqtt_connected or client == nullptr)
 			{

src/TinyMqtt.h

@@ -57,6 +57,7 @@ class MqttMessage
 			Subscribe   = 0x80,
 			SubAck      = 0x90,
 			UnSubscribe = 0xA0,
+			UnSuback		= 0xB0,
 			PingReq     = 0xC0,
 			PingResp    = 0xD0,
 			Disconnect  = 0xE0