Prevent 500 error on login when there's a typo in OpenID URI scheme, such as http;// or http.//

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@3933 e93f8b46-1217-0410-a6f0-8f06a7374b81

vendor/plugins/open_id_authentication/lib/open_id_authentication.rb

@@ -89,7 +89,7 @@ module OpenIdAuthentication
 
       begin
         uri = URI.parse(identifier)
-        uri.scheme = uri.scheme.downcase  # URI should do this
+        uri.scheme = uri.scheme.downcase if uri.scheme # URI should do this
         identifier = uri.normalize.to_s
       rescue URI::InvalidURIError
         raise InvalidOpenId.new("#{identifier} is not an OpenID identifier")