Incorrect plural for seconds in Russian (#1056)

[manlix]

Pull Request Checklist

• 🧪 Added tests for changed code.
• 🛠️ All tests pass when run locally (run tox or make test to find out!).
• 🧹 All linting checks pass when run locally (run tox -e lint or make lint to find out!).
• 📚 Updated documentation for changed code.
• ⏩ Code is up-to-date with the master branch.

Description of Changes

Fix for issue #1056
Closes: #1056

[codecov]

Codecov Report

Merging #1057 (6fce289) into master (3e50ae4) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##            master     #1057   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           10        10           
  Lines         2223      2223           
  Branches       350       350           
=========================================
  Hits          2223      2223           

Impacted Files	Coverage Δ
arrow/locales.py	100.00% <ø> (ø)

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[krisfremen]

LGTM.

thanks @manlix for your contribution and making arrow even better!