🐛 fix: files() function in ci_core_helper.php

Signed-off-by: otengkwame <developerkwame@gmail.com>

Author: otengkwame

Core/helpers/ci_core_helper.php

@@ -506,11 +506,11 @@ function current_route()
      * function to get $_FILES values
      *
      * @param string $index
-     * @return array|string
+     * @return mixed
      */
     function files($index = '')
     {
-        if ($index !== '') {
+        if (isset($_FILES[$index])) {
             return $_FILES[$index];
         }