Fix issue with CMYK images

Previously, if a CMYK cover image were encountered, the update would
fail because the color space was not being handled correctly.

Author: pganssle

src/audio_feeder/updater.py

@@ -874,6 +874,9 @@ def _generate_thumbnail(img_loc: PathType, thumb_loc: PathType) -> None:
     # Don't upscale it
     scale = min([scale, 1])
 
+    if img.mode != "RGB":
+        img = img.convert("RGB")
+
     img.thumbnail((w * scale, h * scale))
     img.save(thumb_loc)
 

tests/test_updater.py

@@ -96,7 +96,6 @@ def patch_book_updater() -> typing.Iterator[None]:
         updater.BookDatabaseUpdater = old_book_updater
 
 
-@pytest.mark.xfail
 def test_update_books(testgen_config: pathlib.Path) -> None:
     with patch_book_updater():
         updater.update(content_type="books")