log: fix crash with DHT log

Commit [0eb462a8: change win32 logger for better readability]
has a regression with DHT logs causing crashes.

DHT logs don't have the '|' character in format string and
this was not checked by the incriminated commit.

Change-Id: Icffc89a2bf178292f183106f0139e0ded9535398
Reviewed-by: Andreas Traczyk <andreas.traczyk@savoirfairelinux.com>