Fix the 'Block WiFi firmware' on 4.38.21908

[obynio]

The Block WiFi firmware upgrade was broken, this change fix it.

Why ?

I want to avoid the 4.38.23038 firmware on my Libra 2 and Clara 2E since the patches for that version has not been released yet. I was tired of getting the update popup.

How ?

Kobo appears to be using the patched firmware upgrade procedure as a fallback method (as proven by the name of the method getBackupUpgradeUrlEv) and is now using getUpgradeServiceUrlEv which contains another similar upgrade check url as the previous one. This change patches both methods.

Prove it

I can't post screenshots for obvious copyright issues, but you can search the above methods by disassembling libnickel.so.1.0.0 like I did to verify my work. I used Hopper Disassembler for my investigations.

Thou shalt test

I tested it on my Libra 2 and Clara 2E running firmware 4.38.21908. Both bypass the 4.38.23038 firmware and still sync. It is also working using a CalibreWeb backend.

[mzelyony]

This worked for me on Forma. Please merge this fix.
Unfortunately 4.38.21908 has become a mainstay for me and I had to block the updates until further.
I suspect I am not the only one rolling back to 4.38.21908 from 23171

[obynio]

I confirm this fix works on 4.38.23171 on Libra 2 and Clara 2E. I don't have any issues on 4.38.23171 with these two devices for me.