It is possible for a thread that creates an MTA to call
CoUninitialize() and not destroy the MTA if another thread has
entered the MTA in the meantime. If the original thread then creates
an STA, subsequent attempts to find the MTA with 'apartment_findfromtid'
will get the original thread's STA. To avoid this, don't set a TID value
in the stub manager IPID value to indicate that the stub resides in the
MTA.
Signed-off-by: Connor McAdams <cmcadams@codeweavers.com>