rec: make chain test more robust and fix max chain size accounting

[omoerbeek]

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)
• checked that this code was merged to master

[omoerbeek]

Hold off, I think I committed the wrong version

[coveralls]

Pull Request Test Coverage Report for Build 10848806902

Details

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• 103 unchanged lines in 11 files lost coverage.
• Overall coverage decreased (-0.03%) to 64.673%

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Files with Coverage Reduction	New Missed Lines	%
pdns/backends/gsql/gsqlbackend.hh	1	97.71%
pdns/misc.cc	2	63.6%
pdns/recursordist/test-syncres_cc2.cc	3	88.85%
pdns/rcpgenerator.cc	3	89.68%
pdns/recursordist/test-syncres_cc1.cc	5	89.75%
pdns/signingpipe.cc	5	83.11%
pdns/recursordist/syncres.cc	11	79.54%
pdns/recursordist/taskqueue.cc	11	34.15%
pdns/recursordist/rec-tcp.cc	14	64.4%
modules/lmdbbackend/lmdbbackend.cc	14	72.5%

Totals
Change from base Build 10847178982:	-0.03%
Covered Lines:	124803
Relevant Lines:	162270

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💛 - Coveralls