Correct printf() format specifiers for long variables in life demo.

Fix asserts in 64 bit builds due to using %u (expecting 32 bit values on a
typical Unix LP64 platform) for 64 bit long values.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65675 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775