Correct logic for WIEC app

[mroda88]

Description

All started at EHN1, when we realised we needed to readout a CRP with half of the FEMBs, because the CRP has only one CRU. We created a configuration that disabled the correct DetStreams. Speicifically, it's a configuration in which instead of 6 wibs, 2 wibs were completely disabled, 2 wibs were completely enabled and 2 wibs had 2 fembs enabled and 2 disabled.

When trying to run, we got an error from the HermesControllerModule, specifically this error here: https://github.com/DUNE-DAQ/hermesmodules/blob/dc08466de673700593d6d6431277de15aaec7a6c/plugins/HermesModule.cpp#L126  with the following  message:

Number of links in configuration (1) and firmware (2) don't matchand we got it for the two wibs which were only half enabled.

We spoke with alessandro and he suggested that the wrong part is here in appmodel, in the WIECApplication::generate_modules(). This fixes the problem.

Type of change

• Documentation (non-breaking change that adds or improves the documentation)
• New feature or enhancement (non-breaking change which adds functionality)
• Optimization (non-breaking change that improves code/performance)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (whatever its nature)

While fixing, the code has been heavily commented to make sure we understand the subtleties of this particular case.

Testing checklist

• Unit tests pass (e.g. dbt-build --unittest)
• Minimal system quicktest passes (pytest -s minimal_system_quick_test.py)
• Full set of integration tests pass (dunedaq_integtest_bundle.sh)
• Python tests pass if applicable (e.g. python -m pytest)
• Pre-commit hooks run successfully if applicable (e.g. pre-commit run --all-files)

This can only be tested with real hardware.

Further checks

• Code is commented where needed, particularly in hard-to-understand areas
• Code style is correct (dbt-build --lint, and/or see https://dune-daq-sw.readthedocs.io/en/latest/packages/styleguide/)
• If applicable, new tests have been added or an issue has been opened to tackle that in the future.
  (Indicate issue here: # (issue))