I’m very sorry.
Y’all will need to boot into recovery mode:
This requires a USB data cable, a computer to connect it to, and fastboot:
fastboot --version
fastboot version 35.0.2-android-tools
This is the most recent version afaics, but older versions should™ work as well.
Follow the instructions linked above. Be sure you use the hybrid-*.imgs that fit your phone
I had my phone on SFOS 4.6.0.15, but only had the hybrid-*.imgs that came with 4.6.0.13. They worked nicely.
If you’re on 5.0 already and don’t have the installation package anymore you can re-download it from Jolla shop.
… Once the telnet connection is established, open a shell and perform the following commands:
mount /dev/mapper/sailfish-root mnt
cd mnt/etc/systemd/system
rm -f hosts-block*
rm *wants/hosts-block*
cd
umount mnt
exit
Then follow the Reverting instructions.
Afterwards it does not matter if you uninstall the application, everything works again except automatic updates. Meaning you still have your adblocking hosts file. If you uninstall, it will revert back to default.
I will now upload Sailfish_OS-Jolla-4.6.0.13-h3213-1.0.0.8 (XA2 Ultra) and Sailfish_OS-Jolla-4.6.0.15-xqau52-1.0.0.16 (10 II) recovery images to my website, with the aforementioned fastboot executable for Linux x86_64.
Again, sorry. I was overly enthusiastic and forgot the dogfooding before uploading.