src/contrib: aaaaand it's gone ;)

contrib/Makefile

 ROOT=	/usr/local/opnsense/contrib
-TREES=	base32 google-api-php-client mobile-broadband-provider-info \
+TREES=	base32 google-api-php-client IXR mobile-broadband-provider-info \
 	simplepie tzdata
 
 .include "../Mk/tree.mk"

plist

@@ -132,7 +132,7 @@
 /usr/local/etc/rc.update_bogons
 /usr/local/etc/rc.update_urltables
 /usr/local/etc/ssl/opnsense.cnf
-/usr/local/opnsense/contrib/IXR_Library.php
+/usr/local/opnsense/contrib/IXR/IXR_Library.php
 /usr/local/opnsense/contrib/base32/Base32.php
 /usr/local/opnsense/contrib/google-api-php-client/Google/Auth/Abstract.php
 /usr/local/opnsense/contrib/google-api-php-client/Google/Auth/AppIdentity.php

src/etc/inc/XMLRPC_Client.inc

 <?php
+
 /**
  *    Copyright (C) 2015 Deciso B.V.
  *
@@ -26,7 +27,8 @@
  *    POSSIBILITY OF SUCH DAMAGE.
  *
  */
-require_once("IXR_Library.php") ;
+
+require_once("IXR/IXR_Library.php");
 
 /**
  * Simple XMLRPC client based on the components from IXR

src/etc/inc/xmlrpc.inc

 <?php
+
 /**
  *    Copyright (C) 2015 Deciso B.V.
  *
@@ -26,7 +27,8 @@
  *    POSSIBILITY OF SUCH DAMAGE.
  *
  */
-require_once("IXR_Library.php") ;
+
+require_once('IXR/IXR_Library.php');
 
 class XMLRPCServer
 {