Option to disable autoupdate

Nobody has claimed this yet.

LeafMiner v 0.0.13

I would like to have an option to disable firmware autoupdate. Default option of checkbox could be **enable**

It looks like firmware can do autoupdate:

```
$ miniterm /dev/ttyACM0 115200
--- Miniterm on /dev/ttyACM0 115200,8,N,1 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
[I] Main: LeafMiner - v.0.0.13 - (C: 2)
[I] Main: ESP32 - Disable WDT
[I] Storage: Setup: OK
[I] AutoUpdate: Connecting to LuckyAP...
[D] AutoUpdate: payload: {
"current": "0.0.13",
"link": "https://github.com/matteocrippa/leafminer/releases/download/v{{version}}/firmware_{{device}}.bin",
"devices": [
"esp8266",
"esp32",
"esp32-s2",
"esp32-s3",
"geekmagic-smalltv",
"lilygo-t-display-s3"
]
}

[D] AutoUpdate: Remote Version: 0.0.13
[D] AutoUpdate: No Updates, Version: 0.0.13
[I] Network: Connecting to LuckyAP...
[D] Network: Connecting to host pool.vkbit.com...
[I] Network: >>> {"id":1,"method":"mining.subscribe","params":["LeafMiner/0.0.13", null]}
```

Autoupdate from 0.0.11 to 0.0.13:

```
$ miniterm /dev/ttyACM1 115200
--- Miniterm on /dev/ttyACM1 115200,8,N,1 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
Main: LeafMiner - v.0.0.11 - (C: 2)
[I] Main: ESP32 - Disable WDT
[I] Storage: Setup: OK
[I] AutoUpdate: Connecting to LuckyAP...
[D] AutoUpdate: payload: {
"current": "0.0.13",
"link": "https://github.com/matteocrippa/leafminer/releases/download[D] AutoUpdate: Written: 1271840
[D] AutoUpdate: Update Success: 1271840
ESP-ROM:esp32s3-20210327
Build:Mar 27 2021
rst:0xc (RTC_SW_CPU_RST),boot:0x2b (SPI_FAST_FLASH_BOOT)
Saved PC:0x420afc66
SPIWP:0xee
mode:DIO, clock div:1
load:0x3fce3808,len:0x4bc
load:0x403c9700,len:0xbd8
load:0x403cc700,len:0x2a0c
entry 0x403c98d0
[I] Main: LeafMiner - v.0.0.13 - (C: 2)
[I] Main: ESP32 - Disable WDT
[I] Storage: Setup: OK
[I] AutoUpdate: Connecting to LuckyAP...
[D] AutoUpdate: payload: {
"current": "0.0.13",
"link": "https://github.com/matteocrippa/leafminer/releases/download/v{{version}}/firmware_{{device}}.bin",
"devices": [
"esp8266",
"esp32",
"esp32-s2",
"esp32-s3",
"geekmagic-smalltv",
"lilygo-t-display-s3"
]
}

[D] AutoUpdate: Remote Version: 0.0.13
[D] AutoUpdate: No Updates, Version: 0.0.13
[I] Network: Connecting to LuckyAP...
```

Firmware 0.0.11 shows information on the display (LILLYGO T-DISPLAY-S3) but firmware 0.0.13 shows only blank screen, like there is a bug in 0.0.13. This is an example why autoupdate of firmware should be optional...

Start by tracing the AutoUpdate flow shown in the serial logs and locating where firmware settings or the device checkbox are handled. Done means users can disable firmware autoupdates, the option defaults to enabled, and updates remain enabled when the setting is unchanged.

Written by the indexing model from the issue text.