fix: minor fix

app.py

@@ -5,6 +5,7 @@ import gradio as gr
 import numpy as np
 import torch
 import math
+import re
 
 from gradio import inputs
 from diffusers import (
@@ -342,7 +343,7 @@ def detect_text(text, state, width, height):
         item = item.strip()
         if item == "":
             continue
-        if item in state:
+        if state is not None and item in state:
             new_state[item] = {
                 "map": state[item]["map"],
                 "weight": state[item]["weight"],