Made path work for lighttpd again as it uses an empty string where Apache returns nil

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@820 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/lib/action_controller/request.rb

@@ -90,7 +90,7 @@ def ssl?
     end
 
     def path
-      path = path_info ? path_info : ( request_uri ? request_uri.split('?').first : '' )
+      (path_info && !path_info.empty?) ? path_info : (request_uri ? request_uri.split('?').first : '')
     end
 
     def port