Bugfix in dropper.py, handle gracefully failure in cleanup

infection_monkey/dropper.py

@@ -133,6 +133,7 @@ class MonkeyDrops(object):
             LOG.warn("Seems like monkey died too soon")
 
     def cleanup(self):
+        try:
             if (self._config['source_path'].lower() != self._config['destination_path'].lower()) and \
                     os.path.exists(self._config['source_path']) and \
                     WormConfiguration.dropper_try_move_first:
@@ -152,3 +153,5 @@ class MonkeyDrops(object):
                     else:
                         LOG.debug("Dropper source file '%s' is marked for deletion on next boot",
                                   self._config['source_path'])
+        except AttributeError:
+            LOG.error("Invalid configuration options. Failing")