Implemented a easy way to get the webinterface SSL secured and accessable over HTTPS by creating certificates with certbot from letsencrypt.

Certificate creation script available in our forum:

https://forum.ts3musicbot.net/viewtopic.php?f=37&t=2894#p11439

Currently available in the BETA channel. Run your bot with -beta to get this feature now.

- Added new start argument "-secure /path/to/keystore.jks" which is required if the webinterface should run SSL secured.

- Added new start argument "-secure-pw keystorePassword" which is required if the webinterface should run SSL secured. A keystore is protected with a password which the bot has to know to encrypt it.