Upgrading older config version from before v1.0 to latest release crashes Picard.

Debug log:

D: 18:16:52,550 tagger.init:202: Starting Picard from ‘/Applications/MusicBrainz Picard.app/Contents/MacOS/picard/tagger.pyc’
D: 18:16:52,551 tagger.init:204: Platform: Darwin-17.7.0-x86_64-i386-64bit CPython 3.7.2
D: 18:16:52,551 tagger.init:205: Versions: Picard 2.1.3, Python 3.7.2, PyQt 5.10.1, Qt 5.10.1, Mutagen 1.42.0, Discid discid 1.1.1, libdiscid 0.6.2, astrcmp Python, SSL Secure Transport, macOS High Sierra (10.13)
D: 18:16:52,551 tagger.init:206: Configuration file path: ‘/Users/susoo/.config/MusicBrainz/Picard.ini’
D: 18:16:52,551 tagger.init:208: User directory: ‘/Users/susoo/Library/Preferences/MusicBrainz/Picard’
D: 18:16:52,552 i18n.setup_gettext:63: No module named ‘Foundation’
D: 18:16:52,553 i18n.setup_gettext:71: Using locale ‘’
D: 18:16:52,554 i18n.setup_gettext:73: Loading gettext translation, localedir=’/Applications/MusicBrainz Picard.app/Contents/MacOS/locale’
D: 18:16:52,554 i18n.setup_gettext:84: [Errno 2] No translation file found for domain: ‘picard’
D: 18:16:52,554 i18n.setup_gettext:103: _ = <function setup_gettext.. at 0x1047032f0>
D: 18:16:52,554 i18n.setup_gettext:104: N_ = <function at 0x106de8e18>
D: 18:16:52,554 i18n.setup_gettext:105: ngettext = <function setup_gettext.._ngettext at 0x10d927d08>
D: 18:16:52,555 i18n.setup_gettext:106: gettext_countries = <function setup_gettext.._gettext_countries at 0x10d927d90>
D: 18:16:52,555 i18n.setup_gettext:107: gettext_attributes = <function setup_gettext.._gettext_attributes at 0x10d927e18>
D: 18:16:52,555 config.run_upgrade_hooks:202: Config upgrade 0.0.0.dev0 -> 1.0.0.final0: In version 1.0, the file naming formats for single and various artist releases were merged.
Traceback (most recent call last):
File “picard/config.py”, line 203, in run_upgrade_hooks
File “picard/config_upgrade.py”, line 81, in upgrade_to_v1_0_0_final_0
TypeError: question(QWidget, str, str, buttons: Union[QMessageBox.StandardButtons, QMessageBox.StandardButton] = QMessageBox.StandardButtons(QMessageBox.Yes|QMessageBox.No), defaultButton: QMessageBox.StandardButton = QMessageBox.NoButton): argument 4 has unexpected type ‘str’

See https://community.metabrainz.org/t/picard-not-launching-in-osx-10-13-6/419775