OZG-7262 OZG-7566 Notify callObserver about error

ozgcloud-common-lib/src/main/java/de/ozgcloud/common/binaryfile/GrpcBinaryFileServerDownloader.java

@@ -109,8 +109,8 @@ public class GrpcBinaryFileServerDownloader<T> {
 			doDownload();
 			sendChunks();
 		} catch (Exception e) {
-			LOG.error("Error while downloading file contents", e);
 			downloadError.set(new TechnicalException("Error while downloading file contents", e));
+			LOG.error(downloadError.get().getMessage(), downloadError.get());
 		} finally {
 			closeOutputStream();
 		}