Allow blank accounts config

piker/brokers/config.py

@@ -114,6 +114,7 @@ def load_accounts() -> dict[str, Optional[str]]:
     if section is None:
         log.warning('No accounts config found?')
 
+    else:
         for brokername, account_labels in section.items():
             for name, value in account_labels.items():
                 accounts[f'{brokername}.{name}'] = value