DCDBPusher: fixing invalid read on RestAPI termination

- Termination of the Rest API relied on a "enabled" flag which was part
of a already-deallocated configuration structure
- Also fixed double termination of the Rest API

dcdbpusher/dcdbpusher.cpp

@@ -111,10 +111,7 @@ void sigHandler(int sig) {
 	//Stop MQTTPusher
 	LOG(info) << "Flushing MQTT queues...";
 	_mqttPusher->stop();
-
-	//Stop https server
-	LOG(info) << "Stopping REST API Server...";
-	_httpsServer->stop();
+	
 }
 
 void printSyntax()
@@ -435,6 +432,7 @@ int main(int argc, char** argv) {
 	LOG(info) << "Signal handlers registered!";
 
 	LOG(info) << "Cleaning up...";
+	bool restAPIEnabled = restAPISettings.enabled;
 	delete _configuration;
 
 	LOG(info) << "Setup complete!";
@@ -445,17 +443,20 @@ int main(int argc, char** argv) {
 	threads.join_all();
 
 	//will only continue if interrupted by SIGINT and threads were stopped
-
+	
 	mqttThread.join();
 	LOG(info) << "MQTTPusher stopped.";
 
+    if (restAPIEnabled) {
+        //Stop https server
+        LOG(info) << "Stopping REST API Server...";
+        _httpsServer->stop();
+        delete _httpsServer;
+    }
+	
 	LOG(info) << "Tearing down objects...";
 	_queryEngine.setNavigator(nullptr);
 	_queryEngine.setSensorMap(nullptr);
-	if (restAPISettings.enabled) {
-		_httpsServer->stop();
-		delete _httpsServer;
-	}
 	delete _mqttPusher;
 	delete _operatorManager;
 	delete _pluginManager;