Add Daniel Austin to contributors for net-mgmt/cacti

He is also the maintainer of these ports:
emulators/atari800
graphics/gocr
irc/miau
irc/undernet-ircu
mail/milter-greylist-devel
mail/opendkim
net/rtg
net-mgmt/klg
sysutils/sas2ircu
x11-wm/ccsm
x11-wm/compiz
x11-wm/compiz-fusion
x11-wm/compiz-plugins-extra
x11-wm/compiz-plugins-main
x11-wm/compiz-plugins-unsupported
x11-wm/compizconfig-backend-gconf
x11-wm/compizconfig-python
x11-wm/emerald
x11-wm/libcompizconfig
x11-wm/simple-ccsm

PR:		219854
Approved by:	garga (mentor)
Differential Revision:	https://reviews.freebsd.org/D11123

en_US.ISO8859-1/articles/contributors/contrib.additional.xml

@@ -2119,6 +2119,11 @@
       <email>hannibal@cyberstation.net</email></para>
   </listitem>
 
+  <listitem>
+    <para>Daniel Austin
+      <email>freebsd-ports@dan.me.uk</email></para>
+  </listitem>
+
   <listitem>
     <para>Daniel B. Hemmerich
       <email>dan@spot.org</email></para>