Sensor expiry alert updated

[Navid200]

Please note that the timings have been updated.

xDrip sensor expiry notifications have been issued 24 hours, 9 hours and 2 hours prior to expiry.

As of the December 15, 2023 release, the timings have been changed to 24 hours, 12 hours, 6 hours and 2 hours prior to expiry.

[Navid200]

https://github.com/NightscoutFoundation/xDrip/releases/tag/2023.12.15