Update app.py

app.py

@@ -35,7 +35,7 @@ def png2svg(png_file,png_b64,svg_file,
 
 
     if len(png_b64):
-        png_file = b64_2_img(png_b64[2:-1])
+        png_file = b64_2_img(png_b64.replace('data:image/png;base64,',''))
     
     params = {'colormode': colormode,
             'hierarchical': hierarchical,