Check file exists before unlinking in 'file_unlink'

inc/functions.php

@@ -795,6 +795,7 @@ function file_unlink($path) {
 		$debug['unlink'][] = $path;
 	}
 
+	if (file_exists($path)) {
 		$ret = @unlink($path);
 
 		    if ($config['gzip_static']) {
@@ -802,6 +803,9 @@ function file_unlink($path) {
 
 			@unlink($gzpath);
 		}
+	} else {
+		$ret = false;
+	}
 
 	if (isset($config['purge']) && $path[0] != '/' && isset($_SERVER['HTTP_HOST'])) {
 		// Purge cache