scheduling option to retry the template render

[bjrmatos]

originally we have avoided adding an automatic retry of failed scheduling renders, because the template linked to the scheduled probably executes some kind of update in script that should not be run more than once. however, maybe adding an option to let you choose if you want to retry the render after fail can be good for some cases, with that user will opt-in to this behavior and can enabled for reports that can be executed more than once.