Incompatible after upgrade PHP5.6 ->PHP7

After upgrading to PHP7 WP was giving a fatal error regarding opentickets.

Fatal error: Switch statements may only contain one default clause in ……nl/httpd.www/wordpress/wp-content/plugins/opentickets-community-edition/inc/ticket/ticket.class.php on line 668

$_GET = wp_parse_args( $_GET, array( 'frmt' => 'html' ) );
		// do something different depending on the requested format
		switch ( $_GET['frmt'] ) {
			default: echo $out; break;
			default: echo apply_filters( 'qsot-display-ticket-output-' . $_GET['frmt'] . '-format', $out, $code, array(
				'ticket' => $ticket,
				'template' => $template,
				'stylesheet' => $stylesheet,
				'page_title' => $page_title,
			) ); break;
		}

		self::_restore_errors();

https://wordpress.org/plugins/opentickets-community-edition/