Connect Assist dropdown text not centered
### Summary
Text in the country dropdown is not centered vertically in tbb-nightly.2023.09.14.
### Steps to reproduce:
**How one can reproduce the issue - this is very important.**
1. In `about:config`, set `torbrowser.debug.censorship_level` to 3.
2. Restart TB
3. Step through Connect Assist until you run into the country dropdown.
### Environment
- tbb-nightly.2023.09.14
### Relevant logs and/or screenshots
<details><summary>Screenshot</summary>
</details>
issue