Switch to ghcr.io for container images..

..following upstream change

compose.yml

@@ -51,7 +51,7 @@ x-environment:
 
 services:
   app:
-    image: mailu/nginx:1.9
+    image: ghcr.io/mailu/nginx:1.9
     logging:
       driver: json-file
     networks:
@@ -98,7 +98,7 @@ services:
       - "redis:/data"
 
   admin:
-    image: ${DOCKER_ORG:-mailu}/${DOCKER_PREFIX:-}admin:1.9
+    image: ${DOCKER_ORG:-ghcr.io/mailu}/${DOCKER_PREFIX:-}admin:1.9
     environment: *default-env
     healthcheck:
       disable: true
@@ -107,7 +107,7 @@ services:
       - "mailu:/data"
 
   imap:
-    image: ${DOCKER_ORG:-mailu}/${DOCKER_PREFIX:-}dovecot:1.9
+    image: ${DOCKER_ORG:-ghcr.io/mailu}/${DOCKER_PREFIX:-}dovecot:1.9
     environment: *default-env
     volumes:
       - "mail:/mail"
@@ -115,7 +115,7 @@ services:
       disable: true
 
   smtp:
-    image: ${DOCKER_ORG:-mailu}/${DOCKER_PREFIX:-}postfix:1.9
+    image: ${DOCKER_ORG:-ghcr.io/mailu}/${DOCKER_PREFIX:-}postfix:1.9
     environment: *default-env
     volumes:
       - "mailqueue:/queue"
@@ -123,7 +123,7 @@ services:
       disable: true
 
   antispam:
-    image: ${DOCKER_ORG:-mailu}/${DOCKER_PREFIX:-}rspamd:1.9
+    image: ${DOCKER_ORG:-ghcr.io/mailu}/${DOCKER_PREFIX:-}rspamd:1.9
     environment: *default-env
     volumes:
       - "rspamd:/var/lib/rspamd"
@@ -132,7 +132,7 @@ services:
       disable: true
 
   webmail:
-    image: ${DOCKER_ORG:-mailu}/${DOCKER_PREFIX:-}rainloop:1.9
+    image: ${DOCKER_ORG:-ghcr.io/mailu}/${DOCKER_PREFIX:-}rainloop:1.9
     environment: *default-env
     networks:
       - default