Mail: fixed overrun of allocated memory (ticket #411).

Reported by Markus Linnala.
diff --git a/src/mail/ngx_mail_smtp_module.c b/src/mail/ngx_mail_smtp_module.c
index cdd4e5e..02bbf1f 100644
--- a/src/mail/ngx_mail_smtp_module.c
+++ b/src/mail/ngx_mail_smtp_module.c
@@ -277,7 +277,6 @@
     p = ngx_cpymem(p, conf->capability.data, conf->capability.len);
 
     p = ngx_cpymem(p, "250 STARTTLS" CRLF, sizeof("250 STARTTLS" CRLF) - 1);
-    *p++ = CR; *p = LF;
 
     p = conf->starttls_capability.data
         + (last - conf->capability.data) + 3;