fix: Fix import of mails with weird Message-IDs
This fixes the import of mails with a Message-ID having more than one <
or >
We migrated some old lists from Mailman2 to Mailman3, but hyperkitty_import
failed for one of the lists because there were two messages with a weird Message-ID in the mbox file. Those Message-IDs were like Message-ID: <<f2862c523f8e7f7534f3bae8971a9c72@example.com>>
. Not sure what's the cause, as the mails are from 2017, but anyway I made a patch to handle this rare case.
Edited by am97