Update bash

Changes:

- https://github.com/tianon/docker-bash/commit/81c7838: Update 5.1-rc to 5.1-rc1
- https://github.com/tianon/docker-bash/commit/db0fc4c: Update devel to 20200924, commit c84a1ebb625289e6b129a167667a78df3407d7d6

library/bash

@@ -3,14 +3,14 @@
 Maintainers: Tianon Gravi <[email protected]> (@tianon)
 GitRepo: https://github.com/tianon/docker-bash.git
 
-Tags: devel-20200921, devel
+Tags: devel-20200924, devel
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 9fc0cdf3d999dfe38bc4d07f73b2b0d83653dde3
+GitCommit: db0fc4c9f5d1b578b9469fa204ed99d493e04834
 Directory: devel
 
-Tags: 5.1-beta, 5.1-rc, rc
+Tags: 5.1-rc1, 5.1-rc, rc
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 7d80c7cc5d829b6be9e04b6b2cba98a228fb67db
+GitCommit: 81c78384e4a7cb7839f75b03ef3dc32453b47b0d
 Directory: 5.1-rc
 
 Tags: 5.0.18, 5.0, 5, latest