Properly handle malformed MQTT messages in CollectAgent.

CollectAgent/collectagent.cpp

@@ -37,7 +37,6 @@ void sigHandler(int sig)
 
 void mqttCallback(SimpleMQTTMessage *msg)
 {
-
   /*
    * Increment the msgCtr/vmsgCtr for statistics.
    */
@@ -73,6 +72,12 @@ void mqttCallback(SimpleMQTTMessage *msg)
           //printf("Val = %" PRIu64 ", timestamp = %" PRIu64 "\n", val, ts);
       }
 
+      //...otherwise this message is malformed -> ignore...
+      else {
+          delete msg;
+          return;
+      }
+
       /*
        * Check if we can decode the message topic
        * into a valid SensorId. If successful, store
@@ -97,7 +102,7 @@ void mqttCallback(SimpleMQTTMessage *msg)
 #endif
           mySensorDataStore->insert(&sid, ts, val);
       }
-#if 0
+#if 1
       else {
           cout << "Wrong topic format: " << msg->getTopic() << "\n";
       }