BUG 12540 "No muestra ningun mensaje cuando el workpace..." SOLVED

- When the workspace is invalid, no displayed any message
- Solved problem, session variables were being destroyed, but now saved if exist any messages

* Available from version ProcessMaker-2.5.2-testing.1
Merge pull request #1963 from victorsl/BUG-12540

BUG 12540 "No muestra ningun mensaje cuando el workpace..." SOLVED