Update to 1.30.1 release

[Wylbur]

Backdrop Release 1.31.0
Release hash 0204d479a71ac692039a9f7b1e50409f

[Wylbur]

Merged pull request #86

[Wylbur]

Created merge Request at docker-library docker-library/official-images#19044

[Wylbur]

Docker image is updated. https://hub.docker.com/_/backdrop