DEVELOPERS: replace Trent Piepho's e-mail address

Trent's e-mail address is no longer working:

<tpiepho@impinj.com>: host us-smtp-inbound-2.mimecast.com[205.139.110.221]
    said: 550 Invalid Recipient -
    https://community.mimecast.com/docs/DOC-1369#550


    [7R954rMIM8GCM0FMERvPAg.us536] (in reply to RCPT TO command)

Use another e-mail that Trent has recently used on the mailing list.

Cc: Trent Piepho <trent.piepho@synapse.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>