Fix "Only resources can modify remote identifiers" when re-editing event
Summary:
... before the resource had time to create it and notify korganizer
about it.
This seems to be a better fix than akonadi commit fbcd065c0dbb,
which for some reason isn't enough (I had the error again in January
2020).
BUG: 407965
Test Plan:
Create event in korganizer, double-click it immediately,
change something, click OK.
Reviewers: dvratil
Reviewed By: dvratil
Differential Revision: https://phabricator.kde.org/D28559