Avoid warning about mixed explicit/implicit returns

[jsoref]

Short description

Use map for getHTTPCounter

This was identified by https://github.com/check-spelling-sandbox/pdns/security/quality/rules/py%2Fmixed-returns

AI was not used for this. I'm using a map because I used one in #16458

Checklist

I have:

• read the CONTRIBUTING.md document
• read and accepted the Developer Certificate of Origin document, including the AI Policy, and added a "Signed-off-by" to my commits
• 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

[coveralls]

Pull Request Test Coverage Report for Build 19231068487

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 366 unchanged lines in 15 files lost coverage.
• Overall coverage increased (+0.05%) to 73.04%

---

Files with Coverage Reduction	New Missed Lines	%
modules/pipebackend/pipebackend.cc	2	60.79%
pdns/recursordist/syncres.cc	2	81.06%
pdns/iputils.cc	3	56.99%
pdns/recursordist/test-syncres_cc2.cc	3	89.18%
pdns/remote_logger.cc	3	57.14%
pdns/dnsdistdist/dnsdist-tcp.cc	4	77.45%
pdns/recursordist/aggressive_nsec.cc	5	66.02%
pdns/signingpipe.cc	5	84.99%
pdns/dnsdistdist/test-dnsdist-opentelemetry_cc.cc	6	79.75%
pdns/misc.cc	6	61.45%

Totals
Change from base Build 19168616743:	0.05%
Covered Lines:	127543
Relevant Lines:	163903

---

💛 - Coveralls

[rgacogne]

Something is wrong:

 FAILED test_DOH.py::TestDoHNGHTTP2::testDOHHTTP1 - NameError: name 'metricMap' is not defined
  FAILED test_DOH.py::TestDoHNGHTTP2Yaml::testDOHHTTP1 - NameError: name 'metricMap' is not defined