server: Only require REG_OPTION_VOLATILE when creating a new key.

[Paul Vriens]

Hi Alexandre,

With this patch the following errors are introduced when starting 
anything on a clean .wine :

err:setupapi:registry_callback could not create key 0x80000002 
L"HARDWARE\\DEVICEMAP\\PARALLEL PORTS"
err:setupapi:registry_callback could not create key 0x80000002 
L"HARDWARE\\DEVICEMAP\\SERIALCOMM"

-- 
Cheers,

Paul.