Update postgres

Changes:

- docker-library/postgres@4c4693e: Merge pull request docker-library/postgres#643 from infosiftr/alpine-jit
- docker-library/postgres@c8bf23b: Add JIT support for Alpine on 11+

Author: docker-library-bot

library/postgres

@@ -11,7 +11,7 @@ Directory: 12
 
 Tags: 12.1-alpine, 12-alpine, alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 34df4665bfdccf28deac2ed2924127b94489a576
+GitCommit: c8bf23b75fa75a99eef9f5ff794c557057e5d8c5
 Directory: 12/alpine
 
 Tags: 11.6, 11
@@ -21,7 +21,7 @@ Directory: 11
 
 Tags: 11.6-alpine, 11-alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 34df4665bfdccf28deac2ed2924127b94489a576
+GitCommit: c8bf23b75fa75a99eef9f5ff794c557057e5d8c5
 Directory: 11/alpine
 
 Tags: 10.11, 10