Can't set the website link clickable of gtk_about

[TualatriX <tualatrix gmail com>]

Hello everyone:

I want my app's about dialog's website link can clickable, but whatever I
try to, it can't work.
I also read some code, such as gedit, nuatilus, their about dialog is using
gtk_about_dialog_set_website_label and gtk_about_dialog_set_website. Their
website can clickable, but why mime isn't like there?

That's the code:
gtk_about_dialog_set_website_label(GTK_ABOUT_DIALOG(dialog),"http://abc.com
");
gtk_about_dialog_set_website(GTK_ABOUT_DIALOG(dialog),"My website");

Thank for the help.