fix: unique html id for checkbox

[alex-sl-eng]

https://zanata.atlassian.net/browse/ZNTA-2549

JIRA issue URL: paste URL here

[description]

Checklist

• JIRA link
• Check target branch
• Make sure all commit statuses are green or otherwise documented reasons to ignore
• QA needs to evaluate against the JIRA ticket
• Changed files and commits make sense for this PR

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[zubot]

This change is 

[huangp]

-(Awaiting review) +Reviewed +(On QA)

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Reviewed 2 of 2 files at r1.
Review status: all files reviewed at latest revision, all discussions resolved.

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Comments from Reviewable

[codecov]

Codecov Report

Merging #848 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##             master    #848   +/-   ##
========================================
  Coverage        34%     34%           
  Complexity     5921    5921           
========================================
  Files          1613    1613           
  Lines         64341   64341           
  Branches       7503    7503           
========================================
  Hits          21876   21876           
  Misses        40482   40482           
  Partials       1983    1983

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[spathare21]

is this targeted for release or master ?

[alex-sl-eng]

cherry-picked into release manually.