banners.php: make banners redirect instead of serving the image directly

banners.php

@@ -1,16 +1,8 @@
 <?php
-function getBannerSrc(){
-	$files = scandir(__dir__.'/banners/');
-	$files = array_diff($files, array('.', '..'));
-	return $files[array_rand($files)];
-}
 
-$filename = getBannerSrc();
-$filename = "banners/" . $filename;
-$fp = fopen($filename, 'rb');
+$files = scandir(__dir__ . '/banners/', SCANDIR_SORT_NONE);
+$files = array_diff($files, ['.', '..']);
 
-header("Content-Type: image/png");
-header("Content-Length: " . filesize($filename)); 
-
-fpassthru($fp);
-?>
+$filename = $files[array_rand($files)];
+header("Location: /banners/$filename", true, 307);
+header('Cache-Control: no-cache');