[1.2] added an explicit error message when a Propel task failed with errors
[1.2] added an explicit error message when a Propel task failed with errors

git-svn-id: 61930ff58dd911725ae5923b6e11d8fc640fbd34@11524 ee427ae8-e902-0410-961c-c3ed070cd9f9

Symfony-Plugins/sfPropel14Plugin