Update app.py

Little bug fixes in image gen

app.py

@@ -297,19 +297,21 @@ def make_image(prompt, user, pwd):
     msg = 'Error: unable to create image.'
     fpath = None
     if user in unames and pwd == pwdList[unames.index(user)]:
-        response = client.images.generate(model='dall-e-2', prompt=prompt,size='512x512',
-               quality='standard', response_format='b64_json')
+        if len(prompt.strip()) == 0:
+            return [None, 'You must provide a prompt']
         try:
+            response = client.images.generate(model='dall-e-2', prompt=prompt,size='512x512',
+               quality='standard', response_format='b64_json')
             image_data = response.data[0].b64_json 
             image = Image.open(BytesIO(base64.b64decode(image_data)))
             fpath = dataDir + user + '.png'
             image.save(fpath)
             msg = 'Image created!'
         except:
-            return [gr.Image(value=None), msg]
+            return [None, msg]
     else:
         msg = 'Incorrect user name or password'
-        return [gr.Image(value=None), msg]
+        return [None, msg]
     return [fpath, msg]