Fixed unscoped env reference (thx krkos@cesnet.cz)

warden3/warden_server/warden_server.py

@@ -812,7 +812,7 @@ class MySQL(ObjectBase):
                             db.query("INSERT INTO event_tag_mapping (event_id,tag_id) VALUES (%s, %s)", (lastid, tag_id))
                     return []
         except Exception as e:
-            exception = self.req.error(message="DB error", error=500, exc=sys.exc_info(), env=env)
+            exception = self.req.error(message="DB error", error=500, exc=sys.exc_info(), env=self.req.env)
             exception.log(self.log)
             return [{"error": 500, "message": "DB error %s" % type(e).__name__}]