[Compose] Maildir GC should have default value of mailcow.conf when running generate_config.sh: 7200h

docker-compose.yml

@@ -242,7 +242,7 @@ services:
         - MAILCOW_PASS_SCHEME=${MAILCOW_PASS_SCHEME:-BLF-CRYPT}
         - IPV4_NETWORK=${IPV4_NETWORK:-172.22.1}
         - ALLOW_ADMIN_EMAIL_LOGIN=${ALLOW_ADMIN_EMAIL_LOGIN:-n}
-        - MAILDIR_GC_TIME=${MAILDIR_GC_TIME:-1440}
+        - MAILDIR_GC_TIME=${MAILDIR_GC_TIME:-7200}
         - ACL_ANYONE=${ACL_ANYONE:-disallow}
         - SKIP_SOLR=${SKIP_SOLR:-y}
         - MAILDIR_SUB=${MAILDIR_SUB:-}