Update postgres

Changes:

- https://github.com/docker-library/postgres/commit/55e3dc0: Merge pull request https://github.com/docker-library/postgres/pull/657 from J0WI/alpine11
- https://github.com/docker-library/postgres/commit/c4b0195: Add home dir
- https://github.com/docker-library/postgres/commit/52814ab: Bump LLVM to 9
- https://github.com/docker-library/postgres/commit/ada31ea: Add postgres directory and user
- https://github.com/docker-library/postgres/commit/1cbd3a1: Upgrade to Alpine 3.11

library/postgres

@@ -11,7 +11,7 @@ Directory: 12
 
 Tags: 12.1-alpine, 12-alpine, alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 0d0485cb02e526f5a240b7740b46c35404aaf13f
+GitCommit: c4b019526a25d1300de77b9699d53ad187cf0dcf
 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: 0d0485cb02e526f5a240b7740b46c35404aaf13f
+GitCommit: c4b019526a25d1300de77b9699d53ad187cf0dcf
 Directory: 11/alpine
 
 Tags: 10.11, 10
@@ -31,7 +31,7 @@ Directory: 10
 
 Tags: 10.11-alpine, 10-alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 0d0485cb02e526f5a240b7740b46c35404aaf13f
+GitCommit: c4b019526a25d1300de77b9699d53ad187cf0dcf
 Directory: 10/alpine
 
 Tags: 9.6.16, 9.6, 9
@@ -41,7 +41,7 @@ Directory: 9.6
 
 Tags: 9.6.16-alpine, 9.6-alpine, 9-alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 0d0485cb02e526f5a240b7740b46c35404aaf13f
+GitCommit: c4b019526a25d1300de77b9699d53ad187cf0dcf
 Directory: 9.6/alpine
 
 Tags: 9.5.20, 9.5
@@ -51,7 +51,7 @@ Directory: 9.5
 
 Tags: 9.5.20-alpine, 9.5-alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 0d0485cb02e526f5a240b7740b46c35404aaf13f
+GitCommit: c4b019526a25d1300de77b9699d53ad187cf0dcf
 Directory: 9.5/alpine
 
 Tags: 9.4.25, 9.4
@@ -61,5 +61,5 @@ Directory: 9.4
 
 Tags: 9.4.25-alpine, 9.4-alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 0d0485cb02e526f5a240b7740b46c35404aaf13f
+GitCommit: c4b019526a25d1300de77b9699d53ad187cf0dcf
 Directory: 9.4/alpine