roundcube: 1.3.10 -> 1.4.0

https://roundcube.net/news/2019/11/09/roundcube-1.4.0-released

* `curl` cmd in the test can fail as roundcube returns a http/401 if
  unauthorized (and we're explicitly requesting the login form). By
  checking if the `persistent_login` plugin is loaded, the assertion is
  still valid)

* Use `$argv[0]` to determine install path in the installer script. I'm
  not exactly sure why, but it seems as `__DIR__` now resolves symlinks
  which breaks the installer if roundcube is in a `buildEnv` with
  third-party plugins.