doc: fix tls "the the" typo

PR-URL: https://github.com/nodejs/node/pull/9665
Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

doc/api/tls.md

@@ -394,7 +394,7 @@ added: v0.3.2
   on any IPv6 address (`::`) when IPv6 is available, or any IPv4 address
   (`0.0.0.0`) otherwise.
 * `callback` {Function} A callback function to be invoked when the server has
-  begun listening the the `port` and `hostname`.
+  begun listening on the `port` and `hostname`.
 
 The `server.listen()` methods instructs the server to begin accepting
 connections on the specified `port` and `hostname`.