bug fix

app.py

@@ -75,6 +75,7 @@ def respond(message, chatHistory):
   except Exception as e:
       errorMessage = {"function":"queryHelper.getQueryForUserInput","error":str(e), "userInput":message}
       saveLog(errorMessage, 'error')
+      return "", chatHistory
   queryGenerated = extractSqlFromGptResponse(botMessage)
   logMessage = {"userInput":message, "tablesColsSelectedByGpt":str(prospectTablesAndCols) , "queryGenerated":queryGenerated, "completeGptResponse":botMessage}
   saveLog(logMessage)