Fixed help message for export's 'jail-whitelist' command to be clearer

[njmurarka]

Description

Fixed the help message for jail-whitelist flag that is part of the daemon export command.

closes: #7666

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• Wrote unit and integration tests
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[codecov]

Codecov Report

Merging #7885 (5f8d767) into master (4b529a4) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #7885   +/-   ##
=======================================
  Coverage   54.16%   54.16%           
=======================================
  Files         612      612           
  Lines       38998    38998           
=======================================
  Hits        21122    21122           
  Misses      15703    15703           
  Partials     2173     2173