<p>Rupert Grint says he and director M Night Shyamalan have been friends for almost 20 years, since the director almost made a Harry Potter movie.</p><p>The star has now worked with Shyamalan on several occasions, appearing in new thriller Knock at the Cabin as well as his role in Shyamalan's mysterious TV series Servant.</p><p>Knock at the Cabin is in UK cinemas from 3 February.</p>
