Fix syntax bug.

app.py

@@ -42,7 +42,7 @@ def fetch_model() -> object:
         _MODEL = psaiops.common.model.get_model(name=_app.MODELS[0], device='cuda', **_MODEL_CFG)
         # give some feedback
         if hasattr(_MODEL, 'name_or_path'):
-            gradio.Info(title='Info', message=f'Successfully switched to `{getattr(_MODEL, 'name_or_path', 'None')}`.', duration=2)
+            gradio.Info(title='Info', message='Successfully switched to `{}`.'.format(getattr(_MODEL, 'name_or_path', 'None')), duration=2)
         else:
             gradio.Warning(title='Warning', message='The GPU time slot expired before the model could be loaded.', duration=4)
     # model object or `None`