one: more secure one_delete

one/models.py

@@ -559,6 +559,7 @@ class Instance(models.Model):
 
     def one_delete(self):
         """Delete host in OpenNebula."""
+        if self.one_id and self.state != 'DONE':
             proc = subprocess.Popen(["/opt/occi.sh", "compute", "delete",
                     "%d" % self.one_id], stdout=subprocess.PIPE)
             (out, err) = proc.communicate()