Update haproxy

Changes:

- https://github.com/docker-library/haproxy/commit/73e4b32: Update to 2.4-dev9

library/haproxy

@@ -4,14 +4,14 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/haproxy.git
 
-Tags: 2.4-dev8, 2.4-dev
+Tags: 2.4-dev9, 2.4-dev
 Architectures: amd64, arm32v5, arm32v7, arm64v8, i386, mips64le, ppc64le, s390x
-GitCommit: 827001ed9bd67c3b50168a978859c5007576d56a
+GitCommit: 73e4b3269e0261f760ac9053eac79c2acdf207b5
 Directory: 2.4-rc
 
-Tags: 2.4-dev8-alpine, 2.4-dev-alpine
+Tags: 2.4-dev9-alpine, 2.4-dev-alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 827001ed9bd67c3b50168a978859c5007576d56a
+GitCommit: 73e4b3269e0261f760ac9053eac79c2acdf207b5
 Directory: 2.4-rc/alpine
 
 Tags: 2.3.5, 2.3, latest