Update ghost

Changes:

- https://github.com/docker-library/ghost/commit/48419df: Update to 3.40.4, ghost-cli 1.15.3
- https://github.com/docker-library/ghost/commit/26eaaec: Update to 3.40.3, ghost-cli 1.15.3

library/ghost

@@ -4,14 +4,14 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/ghost.git
 
-Tags: 3.40.2, 3.40, 3, latest
+Tags: 3.40.4, 3.40, 3, latest
 Architectures: amd64, arm32v7, arm64v8, ppc64le, s390x
-GitCommit: 88f1a1c6d990ebfa5a71c417613ea9b592aec321
+GitCommit: 48419dff4c61427f9789b44c5522559a1cc3b2e2
 Directory: 3/debian
 
-Tags: 3.40.2-alpine, 3.40-alpine, 3-alpine, alpine
+Tags: 3.40.4-alpine, 3.40-alpine, 3-alpine, alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8
-GitCommit: 88f1a1c6d990ebfa5a71c417613ea9b592aec321
+GitCommit: 48419dff4c61427f9789b44c5522559a1cc3b2e2
 Directory: 3/alpine
 
 Tags: 2.38.2, 2.38, 2