rec: Coverity issues missed in last round, all severity "Low"

[omoerbeek]

1587809 Variable copied when it could be moved
1587817 Variable copied when it could be moved
1587819 Variable copied when it could be moved

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 12864148548

Details

• 2 of 3 (66.67%) changed or added relevant lines in 2 files are covered.
• 261 unchanged lines in 25 files lost coverage.
• Overall coverage decreased (-0.001%) to 64.692%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pdns/recursordist/rec-zonetocache.cc	0	1	0.0%

Files with Coverage Reduction	New Missed Lines	%
pdns/validate.cc	1	68.71%
pdns/recursordist/recursor_cache.cc	1	84.09%
pdns/recursordist/sortlist.cc	2	72.94%
pdns/misc.hh	3	87.62%
pdns/packethandler.cc	3	73.05%
pdns/recursordist/negcache.hh	3	82.35%
pdns/recursordist/lwres.cc	3	69.66%
pdns/opensslsigners.cc	3	61.34%
pdns/recursordist/recursor_cache.hh	3	90.1%
pdns/rcpgenerator.cc	3	90.82%

Totals
Change from base Build 12832418127:	-0.001%
Covered Lines:	127779
Relevant Lines:	166435

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💛 - Coveralls