Mail: fixed number of arguments allowed in the listen directive.

src/mail/ngx_mail_core_module.c

diff --git a/src/mail/ngx_mail_core_module.c b/src/mail/ngx_mail_core_module.c
index 4ee7c8d..a5388c8 100644
--- a/src/mail/ngx_mail_core_module.c
+++ b/src/mail/ngx_mail_core_module.c
@@ -41,7 +41,7 @@
       NULL },
 
     { ngx_string("listen"),
-      NGX_MAIL_SRV_CONF|NGX_CONF_TAKE12,
+      NGX_MAIL_SRV_CONF|NGX_CONF_1MORE,
       ngx_mail_core_listen,
       NGX_MAIL_SRV_CONF_OFFSET,
       0,