update the non maingit po files accordingly to normal files.

Originally created by @hefee on #16231 (Redmine)

Yet another a bunch of fixes for puppet-tails. Please do NOT stash my commits, the are touching different this, and it is much easier to find out, why something was changed.

commit b32c517bfef9664e918002adc1b79bcf9f1ea6d0
Author: Sandro Knauß <hefee@debian.org>
Date:   Mon Dec 17 20:26:17 2018 +0100

    redirects stderr -> stdout, to make the cron mails less noisy.

commit da879823da020d3f2c4ad7a3d9553aee7ba8683b
Author: Sandro Knauß <hefee@debian.org>
Date:   Mon Dec 17 18:12:34 2018 +0100

    updates the non maingit po files accordingly to normal files.

commit 5a7540918abfe5370dc5c307facbe4582a3ea388
Author: Sandro Knauß <hefee@debian.org>
Date:   Mon Dec 17 14:36:49 2018 +0100

    refactor update_weblate_git.py

commit e74f3a67b9a5b05ae2b8ed3a9b45e6a1c1dbad5e
Author: Sandro Knauß <hefee@debian.org>
Date:   Mon Dec 17 14:02:33 2018 +0100

    replace loadpo --all with more elaborate solution.

commit 74c314c16761da17bebb5ff6371297e843aa6660
Author: Sandro Knauß <hefee@debian.org>
Date:   Mon Dec 17 13:58:18 2018 +0100

    refactor update-weblate-components.

commit 425e569b911dacf81c010fdec76e366f913cd0f8
Author: Sandro Knauß <hefee@debian.org>
Date:   Mon Dec 17 13:13:34 2018 +0100

    Remove updatechecks --all from weblate cron.

    Upstream write on their documentation, that updatechecks is only needed
    if Weblate is updated. And as one run takes ~2h, we skip it for the
    moment. Discussed with emmapeel and groente.

Feature Branch: https://salsa.debian.org/hefee/puppet-tails/tree/hefee/dev/translation-server

Parent Task: tails#15079 (closed)