widl: Don't make the proxy virtual tables const if they use delegation.

tools/widl/proxy.c

@@ -624,7 +624,8 @@ static void write_proxy(type_t *iface, unsigned int *proc_offset)
   count = count_methods(iface);
 
   /* proxy vtable */
-  print_proxy( "static const CINTERFACE_PROXY_VTABLE(%d) _%sProxyVtbl =\n", count, iface->name);
+  print_proxy( "static %sCINTERFACE_PROXY_VTABLE(%d) _%sProxyVtbl =\n",
+               need_delegation_indirect(iface) ? "" : "const ", count, iface->name);
   print_proxy( "{\n");
   indent++;
   print_proxy( "{\n");