Update app.py

app.py

@@ -149,7 +149,7 @@ class BasicAgent:
 
         elif file_info.endswith(".xlsx"):
             print_coso("Excel file detected")
-            excel_text = self._load_excel_as_text(file_info)
+            excel_text = _load_excel_as_text(file_info)
             print_coso(f"Excel before prompt: {excel_text}")
             prompt = (
                 "The following is the text extracted from an Excel spreadsheet.\n"