Update app.py

app.py

@@ -156,7 +156,7 @@ def image_to_wd14_tags(image: Image.Image, model_name: str, threshold: float,
         tags_pairs = sorted(tags_pairs, key=lambda x: (-x[1], x[0]))
     for tag, score in tags_pairs:
         tag_outformat = tag
-        if not use_spaces:
+        if use_spaces:
             tag_outformat = tag_outformat.replace('_', '-')
         else:
             tag_outformat = tag_outformat.replace(' ', ', ')