Also consider files with upper-case JPG extension

src/main.rs

@@ -181,7 +181,7 @@ async fn update_config_and_image_list_cache_job(
                 // flatten ignores io error while traversing the iterator
                 images.flatten().filter_map(|entry| {
                     let path = entry.path();
-                    if path.extension() == Some(OsStr::new("jpg")) {
+                    if path.extension().unwrap_or_default().to_ascii_lowercase() == "jpg" {
                         Some(path)
                     } else {
                         None