Fix feedback page

Closes #541 (closed)

src/main/java/nl/tudelft/queue/repository/FeedbackRepository.java

@@ -93,6 +93,8 @@ public interface FeedbackRepository
 						.spliterator(),
 				false)
 				.skip(10).collect(Collectors.toList());
-		return new PageImpl<>(feedback, pageable, feedback.size());
+		var page = feedback.subList(pageable.getPageNumber() * pageable.getPageSize(),
+				Math.min(feedback.size(), (pageable.getPageNumber() + 1) * pageable.getPageSize()));
+		return new PageImpl<>(page, pageable, feedback.size());
 	}
 }