B09qmakecoverage.in failing on 'make coverage-html' for accounts-qml-module

Discussing with Francis from here https://code.launchpad.net/~fginther/cupstream2distro-config/remove-coverage-accounts-qml-module/+merge/236320 : a build of accounts-qml-module is failing on `make coverage-html`, will attach log.

No changes to the project's coverage.pri or other build-files, but also no evidence in Jenkins that we've build this before with coverage--I'm able to reproduce the failure locally with pbuilder FWIW, intend to investigate and fix. (Unless the new coverage-building machinery overtakes this.)