refactor: Use second model in example if available, fallback to first

app.py

@@ -347,7 +347,7 @@ with gr.Blocks() as demo:
                     "Use the image as the background with a waveform visualization for the audio positioned in center of the video. Make sure the waveform has a max height of 250 pixels.",
                     0.7,
                     0.1,
-                    list(MODELS.keys())[0],
+                    list(MODELS.keys())[1] if len(MODELS) > 1 else list(MODELS.keys())[0],
                 ],
                 [
                     [