Support self-generated certificates when syncing with nextcloud

[lightzhan-intellif]

I believe many people have a nextcloud server with self-generated certificates, so can quillnote support this case? Thanks for your nice work!

[ConstantMan]

+1

[timemaster67]

You can take a look at how https://github.com/tasks/tasks do it. It has a good looking ui that show to the user that the certificate is not trusted and ask a confirmation. The user can view more details including the certificate fingerprint (if I remember correctly). When the user accept it, this particular certificate is saved and checked again on the next connection to make sure it match what the user accepted.