Update Joplin version and URL

First off, thanks a lot for maintaining your repo. Great work! I stumbled over it while trying to find Joplin on F-Droid, and learning that it's currently unlikely it will ever end up there. So thanks for making it available, much appreciated.

I noticed that the version of Joplin provided on your repo is slightly outdated: currently 1.1.2 is available, while there's already version 1.1.4 on the github releases page.

Also, note that the Web URL has changed from https://joplin.cozic.net/ to https://joplinapp.org/

Thanks!