Tell in the SAL_WARN what apartment mode the thread is in.

It's a bit unclear to me why the code insists on calling this
o2u_attachCurrentThread() function even in cases where it perhaps
should know that it is in the main thread, which has been initialised
as STA by the CoInitialize() in InitSalData().

Change-Id: Ia69e67f8b17ee153d3bcf8ae450d5f413dea2e1a
Reviewed-on: https://gerrit.libreoffice.org/50985Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tor Lillqvist <tml@collabora.com>
(cherry picked from commit 2445d97a)