Update bash

Changes:

- https://github.com/tianon/docker-bash/commit/83b9507: Update to commit 0df4ddca3f371bc258fe4185cdec36fce3e7be7b

library/bash

@@ -3,9 +3,9 @@
 Maintainers: Tianon Gravi <[email protected]> (@tianon)
 GitRepo: https://github.com/tianon/docker-bash.git
 
-Tags: devel-20200214, devel
+Tags: devel-20200221, devel
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 1839ce92ab218a04bbb3d554717d8fd233067bef
+GitCommit: 83b9507cb4aa1f36d4f10fcc348260220bac4f7c
 Directory: devel
 
 Tags: 5.0.16, 5.0, 5, latest