When you undo the last change, the entire content of the editor is selected

### Please answer the following questions for yourself before submitting an issue

- [X] Filters were updated before reproducing an issue
- [X] I checked the [knowledge base](https://adguard.com/kb/) and found no answer
- [X] I checked to make sure that this issue has not already been filed

### AdGuard Extension version

v4, v5

### Browser version

Chrome

### OS version

Windows 10

### Ad Blocking

AdGuard Base filter

### Privacy

_No response_

### Social

_No response_

### Annoyances

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### Security

_No response_

### Other

_No response_

### Language-specific

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### What Tracking protection options do you have enabled?

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### Issue Details

Steps to reproduce:
1. Add few lines
2. Save
3. Edit the first line
4. Save
5. Press Ctrl-Z to undo the last change

### Expected Behavior

The last change is reverted.

### Actual Behavior

**The first** attempt to undo a change causes the editor contents to be selected.

### Screenshots

_No response_

### Additional Information

_No response_