Added CVE reference

Author: rastating

modules/exploits/unix/webapp/maarch_letterbox_unrestricted_file_upload.rb

@@ -26,6 +26,10 @@ def initialize(info = {})
         [
           'Rob Carr <rob[at]rastating.com>'
         ],
+      'References'      =>
+        [
+          ['CVE', '2015-1587']
+        ],
       'DisclosureDate'  => 'Feb 11 2015',
       'Platform'        => 'php',
       'Arch'            => ARCH_PHP,