Sanitize series names in Dovecot maildirs plugin

Author: jb3

ansible/roles/munin-node/templates/plugins/lovelace/dovecot_maildirs.sh.j2

@@ -7,8 +7,10 @@ print_maildir_config() {
     find . -maxdepth 1 -type d \
         | tail -n +2 \
         | awk -F / '{
-            print $2 ".draw AREASTACK"
-            print $2 ".label " $2
+            sanitized = $2
+	        sub(/\./, "_", sanitized)
+            print sanitized ".draw AREASTACK"
+            print sanitized ".label " $2
         }'
 }