Fix setting of listen default

diff --git a/dovecot/save_net.cgi b/dovecot/save_net.cgi
index 54d1517..0df62bd 100755 (executable)
--- a/dovecot/save_net.cgi
+++ b/dovecot/save_net.cgi
@@ -15,7 +15,7 @@ $sslopt = &find("ssl_disable", $conf, 2) ? "ssl_disable" : "ssl";
                ("listen", "ssl_listen");
 foreach $l (@listens) {
        if ($in{$l."_mode"} == 0) {
-               $listen = "";
+               $listen = undef;
                }
        elsif ($in{$l."_mode"} == 1) {
                $listen = "[::]";