flush stderr in wxSafeShowMessage(): this might be unnecessary but definitely doesn't hurt and could be useful if stderr is redirected

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39890 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/log.cpp

@@ -166,6 +166,7 @@ void wxSafeShowMessage(const wxString& title, const wxString& text)
     ::MessageBox(NULL, text, title, MB_OK | MB_ICONSTOP);
 #else
     wxFprintf(stderr, _T("%s: %s\n"), title.c_str(), text.c_str());
+    fflush(stderr);
 #endif
 }