Upstream DNS servers do not support Chinese domain names

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### Prerequisites

Please answer the following questions for yourself before submitting an issue. **YOU MAY DELETE THE PREREQUISITES SECTION.**

- [x] I am running the latest version
- [x] I checked the documentation and found no answer
- [x] I checked to make sure that this issue has not already been filed

### Issue Details

* **Version of AdGuard Home server:**
`v0.106.0-a.95+2a435601`
* **How did you install AdGuard Home:**
`Github releases`
* **How did you setup DNS configuration:**
`System`
* **If it's a router or IoT, please write device model:**
*
* **CPU architecture:**
`AMD64`
* **Operating system and version:**
`Debian10`

### Expected Behavior

Support Chinese domain names

### Actual Behavior

Fill in Upstream DNS servers
`[/恒天.com/]223.5.5.5`
Will not be able to start AdGuardHome