fix: fix syntax errors
diff --git a/modules/upscaler.py b/modules/upscaler.py
index 3aee69db8d2..9d13ee99324 100644
--- a/modules/upscaler.py
+++ b/modules/upscaler.py
@@ -20,7 +20,7 @@ class Upscaler:
     filter = None
     model = None
     user_path = None
-    scalers: []
+    scalers: list = []
     tile = True
 
     def __init__(self, create_dirs=False):

## Description

python syntax error.

## Screenshots/videos:

![image](https://github.com/AUTOMATIC1111/stable-diffusion-webui/assets/40930677/243aa6ca-f863-478f-a169-a433e774d711)

## Checklist:

- [ ] I have read [contributing wiki page](https://github.com/AUTOMATIC1111/stable-diffusion-webui/wiki/Contributing)
- [ ] I have performed a self-review of my own code
- [ ] My code follows the [style guidelines](https://github.com/AUTOMATIC1111/stable-diffusion-webui/wiki/Contributing#code-style)
- [ ] My code passes [tests](https://github.com/AUTOMATIC1111/stable-diffusion-webui/wiki/Tests)
