Prepare v2.2.1 release.

Signed-off-by: crynobone <crynobone@gmail.com>
Ensure subject and data is available to avoid variable not found error
while using queue.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.1' into 2.2
Add changes to changelog.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.2'