remove usage of wxT() macro; it makes example code a bit harder to read

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58212 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/html/helpctrl.h

@@ -240,7 +240,7 @@ protected:
     @code
         // The help can be browsed during the lifetime of this object; when the
         // user quits the help, program execution will continue.
-        wxHtmlModalHelp help(parent, wxT("help"), wxT("My topic"));
+        wxHtmlModalHelp help(parent, "help", "My topic");
     @endcode
 
     @library{wxhtml}