去掉对客户端版本的限制，以便支持更新版本的客户端sdk

broker/src/main/java/io/moquette/spi/impl/ProtocolProcessor.java

@@ -188,8 +188,7 @@ public class ProtocolProcessor {
         String clientId = payload.clientIdentifier();
         LOG.info("Processing CONNECT message. CId={}, username={}", clientId, payload.userName());
 
-        if (msg.variableHeader().version() < MqttVersion.MQTT_3_1_1.protocolLevel() ||
-                msg.variableHeader().version() >= MqttVersion.Wildfire_Max.protocolLevel()) {
+        if (msg.variableHeader().version() < MqttVersion.MQTT_3_1_1.protocolLevel()) {
             MqttConnAckMessage badProto = connAck(CONNECTION_REFUSED_UNACCEPTABLE_PROTOCOL_VERSION);
 
             LOG.error("MQTT protocol version is not valid. CId={}", clientId);