git subrepo commit mailcow/src/mailcow-dockerized

subrepo: subdir:   "mailcow/src/mailcow-dockerized"
  merged:   "308860af"
upstream: origin:   "https://github.com/mailcow/mailcow-dockerized.git"
  branch:   "master"
  commit:   "3f1a5af8"
git-subrepo: version:  "0.4.5"
  origin:   "???"
  commit:   "???"
Change-Id: I5d51c14b45db54fe706be40a591ddbfcea50d4b0
diff --git a/mailcow/src/mailcow-dockerized/data/Dockerfiles/postfix/Dockerfile b/mailcow/src/mailcow-dockerized/data/Dockerfiles/postfix/Dockerfile
index 56b274a..e3c6498 100644
--- a/mailcow/src/mailcow-dockerized/data/Dockerfiles/postfix/Dockerfile
+++ b/mailcow/src/mailcow-dockerized/data/Dockerfiles/postfix/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:buster-slim
+FROM debian:bullseye-slim
 LABEL maintainer "Andre Peters <andre.peters@servercow.de>"
 
 ARG DEBIAN_FRONTEND=noninteractive