mail/dovecot-pigeonhole: upgrade to 0.4.23:

• editheader extension: Corrected the stream position calculations performed while making the modified message available as a stream. Pigeonhole Sieve crashed in LMTP with an assertion panic when the Sieve editheader extension was used before the message was redirected. Experiments indicate that the problem occurred only with LMTP and that LDA is not affected.
• fileinto extension: Fix assert panic occurring when fileinto is used without being listed in the require line, while the copy extension is listed there. This is a very old bug.
• imapsieve plugin: Do not log an error for messages that disappear concurrently while applying Sieve scripts. This is a further improvement on the imapsieve fix in the previous release (which fixed a panic). This event is now logged as a debug message.