fix validator translation
merged branch fzerorubigd/master (PR #7384)

This PR was submitted for the master branch but it was merged into the 2.2 branch instead (closes #7384).

Commits
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7dc1e84 fix validator translation

Discussion
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fix plural string in persian (fa) translation/ validation component

| Q             | A
| ------------- | ---
| Bug fix?      | yes (plural fix in persian translation)
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| License       | MIT