Do not regenerate existing photos

boop.py

@@ -109,10 +109,12 @@ def generate_gallery_dir(output_path, gallery):
 
     for photo in gallery["photos"]:
         photo_output_path = os.path.join(output_path, photo["url"])
-        shutil.copyfile(photo["path"], photo_output_path)
+        if not os.path.exists(photo_output_path):
+            shutil.copyfile(photo["path"], photo_output_path)
 
         thumb_output_path = os.path.join(output_path, photo["thumb_url"])
-        generate_thumb_file(thumb_output_path, photo)
+        if not os.path.exists(thumb_output_path):
+            generate_thumb_file(thumb_output_path, photo)
 
 
 def generate_thumb_file(output_path, photo):