get and set config via mqtt messages

src/mqtt.cpp

@@ -1,12 +1,14 @@
 #include <mqtt.h>
 
 #define STACK_DEPTH 8192
+#define BUFFER_SIZE 2048
 #define PRIOTITY 2
 
 MQTTwrapper::MQTTwrapper() : m_config(Config::getInstance()), m_tcp(NetworkClient()), m_client(PubSubClient(m_tcp)), m_loopHandle(NULL)
 {
     m_client.setServer(m_config.m_mqttHost.c_str(), m_config.m_mqttPort);
-    m_client.setKeepAlive(15);
+    m_client.setKeepAlive(m_config.m_mqttKeepalive);
+    m_client.setBufferSize(BUFFER_SIZE);
     getInstance(this);
 }