Adgurad crashes browser on specific site with Russian filter on

### Issue Details

Waterfox Classic suddenly crashes on either ukr.net or when I click there a link to my inbox mail.ukr.net. Note that if I uploaded page of my mail and then turned on adguard beta extension I can reload my mail. But if I click that link to mail on ukr.net again - it crashes.
Profile is fresh - a day with synced history and just a little bunch of freshly installed extensions which don't interact as crash happens even if I disable all of them except adguard beta.

On another instance of freshly installed browser with synced history on another laptop I get total crash just trying to launch ukr.net page.

Form what I can see it happens with versions of beta Adguard extension but not with non-beta from mozilla addon page.

- **AdGuard version:**
- AdGuard v3.5.5
- **Browser and version:**
- Waterfox Classic (fork of Firefox ESR)
- **Operating system and version:**
- Windows 7
- **Filters you use in AdGuard:**
- At first I thought it crashes even on Basic but then... I found that ONLY Language-Specific Adguard Russian Filter is the one giving this crash.
- **Stealth Mode settings:**
- Disabled
- **Other browser extensions:**
- Non-relevant as I disabled those but here: Always on Top 2.1.25.1, Browsec VPN - Free and Unlimited VPN 3.27.6, Form History Control (II) 2.3.0.0, Google Keep Notes 65.0.0, Hide Caption Titlebar Plus ⁴, In My Pocket 0.11.5, New Tab Tools 89.1, OmniSidebar 1.6.15, Session Manager 0.8.1.13, Stylus 1.5.11, Tab Groups

### Expected Behavior

No crash
### Actual Behavior

Browser crashes
### Screenshots

Screenshot:

### Additional Information
Disabling multiprocessing did not help.