Unable to connect to vtrust-flash

Hey @kueblc!

Thanks for the amazing work you have done on this project and your continued support.

I'm having issues connecting to the SSID vtrust-flash which is being broadcasted, my phone says unable to connect.
I've tried with both **Ubuntu 18.04** and **Raspberry Pi desktop** running on **Oracle VM VirtualBox**. For the wifi adapter I'm using **Ralink RT5370**. I've tried both docker image and regular start_flash.sh method and got stuck at the same step where I'm supposed to connect to vtrust-flash on my phone.

Let me know if you need more information. Appreciate your help and support.

Thanks
Jay

Checking for network interface wlan0... Found.
Checking UDP port 53... Occupied by dnsmasq with PID 2227.
Port 53 is needed to resolve DNS queries
Do you wish to terminate dnsmasq? [y/N] y
Attempting to stop dnsmasq.service
Checking UDP port 67... Available.
Checking TCP port 80... Available.
Checking TCP port 443... Available.
Checking UDP port 6666... Available.
Checking UDP port 6667... Available.
Checking TCP port 1883... Occupied by mosquitto with PID 2484.
Port 1883 is needed to run MQTT
Do you wish to terminate mosquitto? [y/N] y
Attempting to stop mosquitto.service
Checking TCP port 8886... Available.
sudo: ufw: command not found
======================================================
  Starting AP in a screen...
  Starting web server in a screen
  Starting Mosquitto in a screen
  Starting PSK frontend in a screen
  Starting Tuya Discovery in a screen

======================================================

IMPORTANT
1. Connect any other device (a smartphone or something) to the WIFI vtrust-flash
   This step is IMPORTANT otherwise the smartconfig may not work!
2. Put your IoT device in autoconfig/smartconfig/pairing mode (LED will blink fast). This is usually done by pressing and holding the primary button of the device
   Make sure nothing else is plugged into your IoT device while attempting to flash.
3. Press ENTER to continue
^C======================================================

Use start_flash.sh as the main entry point and reproduce the connection failure with the reported Ralink RT5370 adapter in the Ubuntu or Raspberry Pi desktop VirtualBox setup. Compare the regular and Docker startup output, especially the network-interface, firewall, and service checks. Done means a phone can connect to the vtrust-flash SSID and proceed past the displayed prompt.

Written by the indexing model from the issue text.