There is currently no way to specify the sslProtocol. The only workaround is to use a custom server.xml.
The httpsConnector is hardcoded to use TLS.
httpsConnector.setProperty( "sslProtocol", "TLS" );
Due to security reasons, this version is insufficient for many modern browser (chrome and firefox) without having to manually compromise the browser's security settings which expects communication via TLSv1.2