fix error message when empty payload

src/data/updates.rs

@@ -38,7 +38,6 @@ impl Data {
         file.sync_all().await?;
         let file = file.into_std().await;
 
-
         let index_controller = self.index_controller.clone();
         let update = tokio::task::spawn_blocking(move ||{
             let mmap;

src/index_controller/local_index_controller/update_handler.rs

@@ -88,7 +88,7 @@ impl UpdateHandler {
         builder.index_documents_method(method);
 
         let gzipped = true;
-        let reader = if gzipped {
+        let reader = if gzipped && !content.is_empty() {
             Box::new(GzDecoder::new(content))
         } else {
             Box::new(content) as Box<dyn io::Read>