gobject-introspection: Disable package which does currently not build.

[BUILD] env LPATH=.libs  env PYTHONPATH=..:.. UNINSTALLED_INTROSPECTION_SRCDIR=.. UNINSTALLED_INTROSPECTION_BUILDDIR=.. ../tools/g-ir-scanner -v --add-includ
e-path=../gir --add-include-path=. -v --add-include-path=../gir --add-include-path=. --namespace=GLib --nsversion=2.0 --libtool="/bin/sh ../libtool"  --libra
ry=glib-2.0 --pkg=glib-2.0  --noclosure --strip-prefix=g --c-include="glib.h"  -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -DGETTEXT_PACKAGE=Dummy -DGLIB_COMPILATION -D__G_I18N_LIB_H__ /usr/lib/glib-2.0/include/glibconfig.h /usr/include/glib-2.0/glib/*.h ./glib-2.0.c --output GLib-2.0.gir
[BUILD] Traceback (most recent call last):
[BUILD]   File "../tools/g-ir-scanner", line 38, in <module>
[BUILD]     sys.exit(scanner_main(sys.argv))
[BUILD]   File "/usr/src/gobject-introspection-0.6.11/giscanner/scannermain.py", line 248, in scanner_main
[BUILD]     from giscanner.girwriter import GIRWriter as Writer
[BUILD]   File "/usr/src/gobject-introspection-0.6.11/giscanner/girwriter.py", line 30, in <module>
[BUILD]     from .xmlwriter import XMLWriter
[BUILD]   File "/usr/src/gobject-introspection-0.6.11/giscanner/xmlwriter.py", line 70, in <module>
[BUILD]     with LibtoolImporter:
[BUILD] AttributeError: __exit__

diff --git a/pkgs/core/gobject-introspection/gobject-introspection.nm b/pkgs/core/gobject-introspection/gobject-introspection.nm.off
similarity index 100%
rename from pkgs/core/gobject-introspection/gobject-introspection.nm
rename to pkgs/core/gobject-introspection/gobject-introspection.nm.off