Don't require open-uri

It isn't needed here anyway, and is dangerous from a security
perspective - simply doing a require 'ruby-saml' causes every open() in
the calling program to suddenly start accepting any HTTP/FTP URIs, which
could be very surprising and unexpected.

Author: Ari Pollak

lib/onelogin/ruby-saml/logoutresponse.rb

@@ -2,7 +2,6 @@
 require "time"
 require "base64"
 require "zlib"
-require "open-uri"
 
 module Onelogin
   module Saml