Add event command line option crashes Calendar

[FATAL 23:16:19.328968] [e-data-server] e_source_registry_list_sources: assertion 'E_IS_SOURCE_REGISTRY (registry)' failed
[FATAL 23:16:19.329011] [GLib-GObject] g_object_get: assertion 'G_IS_OBJECT (object)' failed
Segmentation fault (core dumped)

Edit: Looks like it is trying to open the dialog before everything has loaded, we can add it to Idle to resolve this but then not all calendars may have finished loading still restricting what they can do...

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