fix warning implode php 7.4

Author: willy68

ActiveRecord.php

@@ -40,11 +40,11 @@ function activerecord_autoload($class_name)
 		foreach ($namespaces as $directory)
 			$directories[] = $directory;
 
-		$root .= DIRECTORY_SEPARATOR . implode($directories, DIRECTORY_SEPARATOR);
+		$root .= DIRECTORY_SEPARATOR . implode(DIRECTORY_SEPARATOR, $directories);
 	}
 
 	$file = "$root/$class_name.php";
 
 	if (file_exists($file))
 		require_once $file;
-}
+}