Russian translation update, for 2.4.x

[ValdikSS]

OlesyaGerasimenko's squashed update from #852 + my changes. The same as #895, accidental repo deletion.

For 2.4.x.

[zdohnal]

@ValdikSS I saw the update brings some duplicates into cups_ru.po - I found duplicated entries of the following strings:

Unable to create PPD file:
Unable to query printer: 
Unable to resolve:
-P filename.ppd
Unable to establish a secure connection to host (%d).
Unable to establish a secure connection to host (certificate chain invalid).
Unable to establish a secure connection to host (certificate not yet valid).
Unable to establish a secure connection to host (expired certificate).
Unable to establish a secure connection to host (host name mismatch).
Unable to establish a secure connection to host (peer dropped connection before responding)
Unable to establish a secure connection to host (self-signed certificate).
Unable to establish a secure connection to host (untrusted certificate).
Unable to establish a secure connection to host.
Unknown directive \"%s\" on line %d of \"%s\" ignored.
ippeveprinter: Unable to open \"%s\": %s on line %d.
ippfind: Unable to browse or resolve: %s
ippfind: Unable to use Bonjour: %s

Can you remove those duplicated entries?

Thank you in advance!

[ValdikSS]

@ValdikSS I saw the update brings some duplicates into cups_ru.po - I found duplicated entries of the following strings:
Can you remove those duplicated entries?

Thank you in advance!

Done

[ValdikSS]

Any comments, updates?