DNScrypt - key validity period

### Prerequisites

- [X] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a) and found no answer

- [X] I have searched other issues and found no duplicates

- [X] I want to report a bug and not [ask a question or ask for help](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a)

- [X] I have set up AdGuard Home correctly and [configured clients to use it](https://github.com/AdguardTeam/AdGuardHome/wiki/Clients). (Use the [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions/categories/q-a) for help with installing and configuring clients.)

### Platform (OS and CPU architecture)

Linux, ARM64

### Installation

GitHub releases or script from README

### Setup

On one machine

### AdGuard Home version

v0.107.36

### Action

The the key validity period using dnscrypt on Adguard Home is excessively long.

`[2023-08-23 10:55:48] [INFO] [2.dnscrypt-cert.testserver.local] the key validity period for this server is excessively long (365 days), significantly reducing reliability and forward security.`

### Expected result

Reduse the key validity period for extra security. After all, the use of DNScrypt is there for one reason only. Security.

### Actual result

The key validity is 365 days long.

### Additional information and/or screenshots

_No response_