Replace alphanumeric and operator spelling

Some (all?) versions of MSVC++ doesn't like it without including
<ciso646>, and we don't really want to use the alternate operator
spellings anyway.

src/scripting/lua_gui2.cpp

@@ -277,7 +277,7 @@ int show_message_dialog(lua_State *L, CVideo & video)
 		options, &chosen_option
 	);
 
-	if (!has_input and options.empty()) {
+	if (!has_input && options.empty()) {
 		lua_pushinteger(L, dlg_result);
 	} else {
 		lua_pushinteger(L, chosen_option + 1);