Remove unused function declaration

src/installerprompt.h

@@ -51,7 +51,6 @@ private:
 
     void handleWifiConnection(const QString &ssid, bool recoverFromWrongPassword = false);
     QString promptForWifiPassword(const QString &ssid, bool isWrongPassword = false);
-    void connectToWifi(const QString &ssid, const QString &password, bool recoverFromWrongPassword = false);
     void initLanguageComboBox();
     QStringList getAvailableLanguages();
     void showWifiOptions();