Add support for deploying to the Zyxel GS1900 line of switches as long
as those switches are running at least firmware V2.80.
Tested on a Zyxel GS1900-8 and GS1900-24E
Resolves#5042
Since the server in mainland China cannot connect to Telegram, add the TELEGRAM_BOT_URLBASE environment variable
Please add the proxy address you set. If this variable is not added, it will be the default value (https://api.telegram.org)
It was reported in issue #6267 that the private key was leaked when
using the DEPLOY_HAPROXY_HOT_UPDATE=yes feature.
Indeed, the debugging code which sends commands to HAProxy was using
_debug even when passing the private key.
This patch fixes the issue by using _secure_debug when doing that.