arb1 does not approve tokens by default

src/dexorder/metadata.py

@@ -160,6 +160,8 @@ def get_metadata(addr=None, *, chain_id=None):
     if metadata is NARG:
         if config.metadata is None or generating_metadata:
             metadata = None
+        elif config.metadata == '':
+            metadata = None
         else:
             try:
                 with open(config.metadata) as file: