Add missing Russian translation

[h3ssan]

Contribution Guidelines

• I've read the contribution guidelines and wholeheartedly agree them

What does this PR include?

• Add missing translation for Russian language in the /debug route.

Short Description

Affected Containers

• php-fpm-mailcow

Did you run tests?

Yes, I did check the website's admin panel

What did you tested?

• /debug website's translation

What were the final results? (Awaited, got)

[MAGICCC]

Thanks
You may also checkout https://translate.mailcow.email/engage/mailcow-dockerized/

[Habetdin]

@MAGICCC some of these strings (e.g. mailcow_system) were suggested in Weblate 1+ year ago but weren't approved, and the regular users (Users, Viewers) cannot approve such strings :(

[MAGICCC]

@Habetdin Yes, they are a lot of strings (across all languages actually) with suggestion made by anonymous. Those are done by Deepl plugin of weblate and since I do not understand 98% of the language I dont want to approve them. I would be very happy if you can compile me a list or redo the suggestions for Russian.