Fix crash on idle status change with 64 bit architectures.

bool and gboolean are not necessarily the same size on all
architectures, and if gboolean is larger than bool then passing it
as an argument to g_object_get can trash the stack.  In this case
overwriting some of the session pointer.

Change-Id: Iaa7be6a327e9f69212bd7d5bb372d33f2026db0f
Reviewed-by: Andy Nichols <andy.nichols@digia.com>