Use committer date for atom feed entry updated element

Committer date reflects the most recent change and is used for ordering
the log page (author date is still available in published element of the
feed entry).

Signed-off-by: Chris Mayo <aklhfex@gmail.com>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

ui-atom.c

@@ -24,7 +24,7 @@ void add_entry(struct commit *commit, char *host)
 	html_txt(info->subject);
 	html("</title>\n");
 	html("<updated>");
-	cgit_print_date(info->author_date, FMT_ATOMDATE, 0);
+	cgit_print_date(info->committer_date, FMT_ATOMDATE, 0);
 	html("</updated>\n");
 	html("<author>\n");
 	if (info->author) {