rec: Backport 14991 to rec 5.2.x: zap dangling symlink

[omoerbeek]

(cherry picked from commit 472b550)

Backport of #14991

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 12632560274

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 21 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.009%) to 66.44%

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Files with Coverage Reduction	New Missed Lines	%
pdns/recursordist/syncres.cc	3	79.46%
pdns/iputils.cc	3	33.95%
pdns/recursordist/test-syncres_cc1.cc	15	89.02%

Totals
Change from base Build 12313058664:	-0.009%
Covered Lines:	57874
Relevant Lines:	77110

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💛 - Coveralls