gio/gdbusaddress.c: Silence RunDLL errors

The RunDLL command call during get_session_address_dbus_launch() was
expecting _g_win32_run_session_bus@16 and g_win32_run_session_bus
on Win32 and Win64 respectively at least when GLib is compiled with MSVC,
not g_win32_run_session_bus@16, which caused annoying RunDLL error dialogue
boxes to show up during the use of GtkApplication (such as when running
gtk3-demo-application on Windows), prevented GtkApplication items from
being run for more than one time during the lifespan of the program,
and this also interfered with some GTK+ tests, causing them to fail.

Update accordingly to address the issue.