Ensure a folder's sidebar children are re-added when its type changes.

Fixes issue #11
6 jobs for wip/11-special-folder-children-0.12 in 25 minutes and 5 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #57208
debian

00:05:42

passed #57210
deb-package

00:22:17

passed #57207
fedora

00:22:48

failed #57682
flatpack-package

00:02:16

passed #57209
ubuntu

00:13:06

failed #57211
flatpack-package

00:19:39

 
Name Stage Failure
failed
flatpack-package Build
Cloning into '/builds/GNOME/geary'...
Checking out 903719bd as wip/11-special-folder-children-0.12...
Updating/initializing submodules...
Checking cache for flatpack-package-wip-11-special-folder-children-0-12...
Successfully extracted cache
$ flatpak-builder flatpak-build org.gnome.Geary.json
error: org.gnome.Sdk/x86_64/3.28 not installed
Failed to init: Unable to find sdk org.gnome.Sdk version 3.28
ERROR: Job failed: exit code 1