dnsdist: ChangeLog and secpoll update for 1.8.3

[rgacogne]

Short description

Checklist

I have:

• read the CONTRIBUTING.md document
• compiled this code
• tested this code
• included documentation (including possible behaviour changes)
• documented the code
• added or modified regression test(s)
• added or modified unit test(s)

[coveralls]

Pull Request Test Coverage Report for Build 7220234977

Warning: This coverage report may be inaccurate.

We've detected an issue with your CI configuration that might affect the accuracy of this pull request's coverage report.
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A quick fix for this PR: rebase it; your next report should be accurate.

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 310 unchanged lines in 6 files lost coverage.
• Overall coverage increased (+1.0%) to 57.693%

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Files with Coverage Reduction	New Missed Lines	%
pdns/sodcrypto.cc	1	90.51%
pdns/sstuff.hh	1	61.99%
pdns/misc.cc	2	62.69%
pdns/stubresolver.cc	3	81.63%
pdns/recursordist/test-syncres_cc1.cc	6	89.03%
modules/lmdbbackend/lmdbbackend.cc	297	72.39%

Totals
Change from base Build 7207845750:	1.0%
Covered Lines:	107584
Relevant Lines:	155151

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💛 - Coveralls