don't define g_UnicodeSubsetTable in non-Unicode build (fixes gcc warning)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@41759 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/richtext/richtextsymboldlg.cpp

@@ -111,6 +111,7 @@ typedef enum
 } wxUnicodeSubsetCodes;
 
 /* Unicode subsets */
+#ifdef __UNICODE__
 
 static struct
 {
@@ -261,6 +262,8 @@ static struct
     U_SPECIALS, wxT("Specials") }
 };
 
+#endif // __UNICODE__
+
 #if 0
 // Not yet used, but could be used to test under Win32 whether this subset is available
 // for the given font. The Win32 function is allegedly not accurate, however.