fix build date parsing from php if php patched with suhosin:

$ php -v
PHP 5.3.27 with Suhosin-Patch (cli) (built: Aug 30 2013 04:30:30) 
Copyright (c) 1997-2013 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2013 Zend Technologies

--- ohai-6.16.0/lib/ohai/plugins/php.rb	2013-01-17 21:03:16.000000000 +0200
+++ ohai-6.16.0/lib/ohai/plugins/php.rb	2013-09-11 15:26:11.000000000 +0300
@@ -26,10 +26,10 @@
 
 status, stdout, stderr = run_command(:no_status_check => true, :command => "php -v")
 if status == 0
-  output = stdout.split
-  if output.length >= 6
+  output = /PHP (\S+).+built: ([^)]+)/.match(stdout)
+  if output
     php[:version] = output[1]
-    php[:builddate] = "%s %s %s" % [output[4],output[5],output[6]]
+    php[:builddate] = output[2]
   end
   languages[:php] = php if php[:version]
 end