Configurable number of rotated log files

PR - https://github.com/docker-mailserver/docker-mailserver/pull/3907/files

Signed-off-by: Aldo Maria Vizcaino <aldo.vizcaino87@gmail.com>

Author: AlMaVizca

charts/docker-mailserver/values.yaml

@@ -131,6 +131,7 @@ deployment:
     LOGWATCH_SENDER: 
     REPORT_RECIPIENT: 
     REPORT_SENDER: 
+    LOGROTATE_COUNT: 4
     LOGROTATE_INTERVAL: weekly
     POSTFIX_REJECT_UNKNOWN_CLIENT_HOSTNAME: 0
     POSTFIX_INET_PROTOCOLS: all