Only found the exception with the Debugger, when exit the swriter.
The appliction stop the SalTimer, but the own message
(SAL_MSG_TIMER_CALLBACK) is in the message-queue and restart the
timer again. After that, the SalData would be delete and then in
SalTimerProc use the SalData, then exception.

Change-Id: I8e02a38d4e741cfd31de605cb5b172b28a0909fb
Reviewed-on: https://gerrit.libreoffice.org/15649Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>