Update app.py

app.py

@@ -16,8 +16,7 @@ def setup_avif_decode():
 setup_avif_decode()
 
 
-def convert_avif_to_png(avif_file):
-    def convert_avif_to_png(avif_files):
+def convert_avif_to_png(avif_files):
     output_paths = []
     for avif_file in avif_files:
         avif_path = avif_file.name