Fix restoring locale in wxCmdLineParser::SetArguments().

We need to call setlocale(NULL) to query the current locale, setlocale("")
returns the newly set locale and not the original one.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@77542 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775