securepages_match() called multiple times per page

In the hook_init(), this module calls securepages_redirect(), which calls securepages_match(). securepages_match() is then called in a form_alter, so there can be a case where securepages_match() is called multiple times for the same path. How about we add a static variable to reduce the overhead? Patch will be attached.

  // Prevent function from being called multiple times unnecessarily.
  static $securepages_match = array();
  if (in_array($path, $securepages_match)) {
    return;
  }
  array_push($securepages_match, $path);