Revert "registry/client: set Accept: identity header when getting layers"

This reverts commit 16f086a0ec.

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

registry/client/transport/http_reader.go

@@ -180,7 +180,6 @@ func (hrs *httpReadSeeker) reader() (io.Reader, error) {
 		// context.GetLogger(hrs.context).Infof("Range: %s", req.Header.Get("Range"))
 	}
 
-	req.Header.Add("Accept-Encoding", "identity")
 	resp, err := hrs.client.Do(req)
 	if err != nil {
 		return nil, err