Fix avatar position in mention box.

Signed-off-by: Ivan Sein <ivan@nextcloud.com>

css/comments.scss

@@ -292,7 +292,7 @@ body:not(#body-public) #commentsTabView .comment .authorRow:not(.currentUser):no
 		width: 16px;
 		vertical-align: middle;
 		padding: 1px;
-		margin-top: -2px;
+		margin-top: -4px;
 		margin-left: 0;
 		margin-right: 2px;
 	}