gtk2-ng introspection compile fix

Easy 7.3.9 has gtk-ng, compiled with "--introspection=no". This was raised as an issue:

https://git.devuan.org/Daemonratte/gtk2-ng/issues/21

Great, now fixed.

We have been discussing gtk2-ng in the forum:

https://forum.puppylinux.com/viewtopic.php?t=16898  

Tags: easy