#468 Gabber segfaults exactly once a month

[Alfred Morgan]

Every time someone sends me a message on the first of
the month (today is 3-1-2004 BTW) Gabber crashes. I
run gabber all month long with no crashing until the
first of the month. It seems that gabber expects the
user's history file to exist but since the month rolled
over it now can't find the history file for that month
and crashes. you need to create the history file for
that user when it can't find it or write to it when the
date changes or for any other reason.

-alfred