Propagate Exceptions up in Celery-Eager-Mode

When running in celery-eager mode, the celery machinery
hides all exceptions inside "celery tasks" (you can find
out about them on the task handle somehow). Currently much
better to propagate them straight up, so they're visible on
the console.

mediagoblin/celery_setup/__init__.py

@@ -140,6 +140,7 @@ def setup_celery_from_config(app_config, global_config,
 
     if force_celery_always_eager:
         celery_settings['CELERY_ALWAYS_EAGER'] = True
+        celery_settings['CELERY_EAGER_PROPAGATES_EXCEPTIONS'] = True
 
     __import__(settings_module)
     this_module = sys.modules[settings_module]