Messaging Framework integration fails on license check

Like seen e.g. here: https://codereview.qt-project.org/#/c/233234/

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/qtqa-latest/tests/prebuild/license/tst_licenses.pl line 434.
not ok 215 - No reference text for license type LGPL21 in src/libraries/qmfwidgets/emailfolderview.cpp, line 8

1. Failed test 'No reference text for license type LGPL21 in src/libraries/qmfwidgets/emailfolderview.cpp, line 8'

[...]

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Seems to boil down to qtbase commit a6514ddd333:

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 Author: Jani Heikkinen <jani.heikkinen@qt.io>
Date: Thu Jan 11 13:13:53 2018 +0200

Fix license headers

Remove usage of outdated header.LGPL21 and replace those with proper
one (header.LGPL in src, header.GPL-EXCEPT in tests)

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So either a) above change wasn't fully proper and lgpl21 header should be brought back for projects like this, or b) qt infrastructure shouldn't anymore host any lgpl21 projects and messaging framework should be relicensed. Right?

I'm hoping the case would be the former. We, as in Jolla, have been de facto maintaining messaging framework for past years and at the moment we wouldn't like to change the license here. We have bunch of changes that haven't been upstreamed, new ones coming up now like above, and I've been trying to push external changes to upstream first. If that cannot happen, we'll soon have a fork that cannot be upstreamed due to contribution agreement etc.