[Python] Fix generated bindings for interfaces.
[Python] Fix generated bindings for interfaces.

The generated .defs files were using define-object instead of
define-interface for the interfaces. We sed this right in order to keep
the generated nature of the .defs files.

gregier/libpeas,chergert/libpeas,Distrotech/libpeas,GNOME/libpeas,gregier/libpeas,GNOME/libpeas,Distrotech/libpeas,gregier/libpeas,chergert/libpeas,Distrotech/libpeas,chergert/libpeas,gregier/libpeas