wxWidgets requires wchar_t for some time now; wx/chartype.h has a check
to fail complation without it. Simplify code by removing now-dead code
for the !wxUSE_WCHAR_T case.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@63991 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775