Avoid cert verify issues via https clone on Linux

[craigds]

Description

On a fresh Ubuntu install (tested with 21.04) kart clone wasn't using the certificate bundle included with it, and thus produced this error when cloning things:

root@a0cd8d48a21e:/downloads# kart clone https://github.com/Georepublic/kart-repo.git
Cloning into '/downloads/kart-repo.git/.clone'...
fatal: unable to access 'https://github.com/Georepublic/kart-repo.git/': error setting certificate verify locations:
  CAfile: /etc/pki/tls/certs/ca-bundle.crt
  CApath: none

Todo

• Actually test the deb build on ubuntu to make sure the issue goes away
• figure out why this isn't happening in the e2e test in github actions?

Related links:

fixes #533

Checklist:

• Have you reviewed your own change?
• Have you included test(s)?
• Have you updated the changelog?

[craigds]

I tested this and the built deb works fine in Ubuntu 21.04 now 👍

[rcoup]

Can we add a test for it into test/scripts/e2e-1.sh? Something basic like kart git ls-remote https://github.com/git/git.git HEAD. Need to check it fails first though 😃

[craigds]

I added the E2E test, and also cherry-picked it to master, and it failed on master but passed on this branch 👍