fix tax convergence reporting in modelSummary

[orichters]

Purpose of this PR

• was broken since all iterations were tracked, as p80_convNashTaxrev was replaced by p80_convNashTaxrev_iter
• now again prints the following to the log and to remindstatus on the cluster:

No failed markets in fulldata.gdx.
Failed tax convergence in fulldata.gdx:
 - IND: 2080
 - MEA: 2070, 2080, 2090
 - REF: 2070, 2080, 2090, 2100, 2110, 2130, 2150
 - SSA: 2070, 2080

Type of change

• Bug fix

Checklist:

• My code follows the coding etiquette
• I performed a self-review of my own code
• I explained my changes within the PR, particularly in hard-to-understand areas
• I checked that the in-code documentation is up-to-date
• I adjusted the reporting in remind2 where it was needed
• I adjusted forbiddenColumnNames in readCheckScenarioConfig.R in case the PR leads to deprecated switches
• All automated model tests pass (FAIL 0 in the output of make test)
• No need to update the changelog CHANGELOG.md