prevent crash when removing remote with no urls

hello

Merge pull request jesseduffield#1051 from jesseduffield/go-1.10-compat

gui: fix go-1.10 compatibility

workflows: don't sign commit

workflows: run CD on Ubuntu 20.04

So we can get newer git-buildpackage

Merge pull request jesseduffield#1049 from jesseduffield/cd-update-ppa

workflows: update PPA repo as part of CD process

update in-app release notes

fix up intro text even more

smarter checking of git version

smarter checking of git version