update README to link to http://z-push.org/ now that we are on the main line

README.md

@@ -28,7 +28,7 @@ It is a one-click email appliance. There are no user-configurable setup options.
 
 The components installed are:
 
-* SMTP ([postfix](http://www.postfix.org/)), IMAP ([dovecot](http://dovecot.org/)), CardDAV/CalDAV ([Nextcloud](https://nextcloud.com/)), Exchange ActiveSync ([z-push](https://github.com/fmbiete/Z-Push-contrib))
+* SMTP ([postfix](http://www.postfix.org/)), IMAP ([dovecot](http://dovecot.org/)), CardDAV/CalDAV ([Nextcloud](https://nextcloud.com/)), Exchange ActiveSync ([z-push](http://z-push.org/))
 * Webmail ([Roundcube](http://roundcube.net/)), static website hosting ([nginx](http://nginx.org/))
 * Spam filtering ([spamassassin](https://spamassassin.apache.org/)), greylisting ([postgrey](http://postgrey.schweikert.ch/))
 * DNS ([nsd4](https://www.nlnetlabs.nl/projects/nsd/)) with [SPF](https://en.wikipedia.org/wiki/Sender_Policy_Framework), DKIM ([OpenDKIM](http://www.opendkim.org/)), [DMARC](https://en.wikipedia.org/wiki/DMARC), [DNSSEC](https://en.wikipedia.org/wiki/DNSSEC), [DANE TLSA](https://en.wikipedia.org/wiki/DNS-based_Authentication_of_Named_Entities), and [SSHFP](https://tools.ietf.org/html/rfc4255) records automatically set