Update bash

Changes:

- https://github.com/tianon/docker-bash/commit/5e48786: Update devel to 20210315, commit 83c4ad27c7f1284ecb5db6e2f1afc0c553d5fcf3
- https://github.com/tianon/docker-bash/commit/8789b92: Fix Git version assumption
- https://github.com/tianon/docker-bash/commit/f045e71: Update "versions.sh" to be more forgiving about commit messages (and more strict about only updating once a week)
- https://github.com/tianon/docker-bash/commit/3ff1fb5: Update devel to 20210305, commit 11bf534f3628cc0a592866ee4f689beca473f548

library/bash

@@ -3,9 +3,9 @@
 Maintainers: Tianon Gravi <[email protected]> (@tianon)
 GitRepo: https://github.com/tianon/docker-bash.git
 
-Tags: devel-20210301, devel
+Tags: devel-20210315, devel
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 456845a14feab72dee30a07766337242276e4e1e
+GitCommit: 5e48786cd7ca85ac0a8ca8113c885a4e1d4da07d
 Directory: devel
 
 Tags: 5.1.4, 5.1, 5, latest