Fix precedence error in failsafe rescue. Closes #8625.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7006 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

railties/lib/dispatcher.rb

@@ -40,7 +40,7 @@ def dispatch(cgi = nil, session_options = ActionController::CgiRequest::DEFAULT_
       end
     rescue Exception => exception  # errors from CGI dispatch
       failsafe_response(cgi, output, '500 Internal Server Error', exception) do
-        controller ||= ApplicationController rescue ActionController::Base
+        controller ||= (ApplicationController rescue ActionController::Base)
         controller.process_with_exception(request, response, exception).out(output)
       end
     ensure