Log database errors instead of showing them.

display_errors is off unless DISPLAY_ERRORS is set in .env.

feed.php

@@ -13,7 +13,7 @@ header("Content-Type: application/rss+xml");
 
 // Set up a RSS "header"
 $query = "SELECT MAX(`date`) FROM $table;";
-$result = $db->query($query) or die("Query failed : ".$db->error);
+$result = $db->query($query) or db_fail();
 $most_recent = $result->fetch_row();
 $now = date("D, d M Y H:i:s O");