Merge pull request #7 from damdo/fix-keepalive

fix: keepalive behviour when set to 0

Author: imbeacon

src/PubSubClient.cpp

@@ -370,7 +370,7 @@ uint32_t PubSubClient::readPacket(uint8_t* lengthLength) {
 boolean PubSubClient::loop() {
     if (connected()) {
         unsigned long t = millis();
-        if ((t - lastInActivity > this->keepAlive*1000UL) || (t - lastOutActivity > this->keepAlive*1000UL)) {
+        if (((t - lastInActivity > this->keepAlive*1000UL) || (t - lastOutActivity > this->keepAlive*1000UL)) && keepAlive != 0) {
             if (pingOutstanding) {
                 this->_state = MQTT_CONNECTION_TIMEOUT;
                 _client->stop();