Improve Wifi connection and portal

src/NukiNetwork.h

@@ -26,6 +26,7 @@ public:
     void reconfigureDevice();
     void scan(bool passive = false, bool async = true);
     bool isApOpen();
+    bool isConnected();
     void clearWifiFallback();
 
     const String networkDeviceName() const;
@@ -44,7 +45,6 @@ public:
     void disableAutoRestarts(); // disable on OTA start
     void disableMqtt();
     String localIP();
-    bool isConnected();
 
     void subscribe(const char* prefix, const char* path);
     void initTopic(const char* prefix, const char* path, const char* value);