fix crash when displaying in drops

slk/repl/repl.py

@@ -349,7 +349,8 @@ def do_balance(self: SidechainRepl, line: str) -> None:
             elif not chains[0].is_asset_alias(asset_alias):
                 print(f"Error: {asset_alias} is not a valid asset alias")
                 return
-            assets = [[chains[0].asset_from_alias(asset_alias)]]
+            else:
+                assets = [[chains[0].asset_from_alias(asset_alias)]]
         else:
             # XRP and all assets in the assets alias list
             assets = [