SeriesService.addImageToSeries(): improve log message.

No functional changes.

Author: php-coder

src/main/java/ru/mystamps/web/service/SeriesServiceImpl.java

@@ -171,7 +171,7 @@ public void addImageToSeries(AddImageDto dto, Integer seriesId, Integer userId)
 		seriesDao.markAsModified(seriesId, new Date(), userId);
 
 		LOG.info(
-			"Image #{} was added to series #{} by user #{}",
+			"Image #{} has been added to series #{} by user #{}",
 			imageId,
 			seriesId,
 			userId