build: Do not scan glib-autocleanups.h for GLib-2.0.gir

Since autoptr typedefs are filtered out (bug #755882), scanning this header
is useless. It can cause warnings due to not #including all the headers
whose types it references:
   /usr/include/glib-2.0/glib/glib-autocleanups.h:41: syntax error,
   unexpected typedef-name, expecting identifier or '(' in 'typedef
   GAsyncQueue *GAsyncQueue_autoptr;' at 'GAsyncQueue_autoptr'

Fix that by filtering it out of the list of headers to scan.

https://bugzilla.gnome.org/show_bug.cgi?id=768816

Makefile-gir.am

@@ -78,7 +78,7 @@ GLib_2_0_gir_CFLAGS = \
             -D__G_I18N_LIB_H__
 GLib_2_0_gir_FILES =  \
                 $(GLIB_LIBDIR)/glib-2.0/include/glibconfig.h \
-		$(GLIB_INCLUDEDIR)/glib/*.h \
+		$(filter-out $(GLIB_INCLUDEDIR)/glib/glib-autocleanups.h,$(wildcard $(GLIB_INCLUDEDIR)/glib/*.h)) \
 		$(GLIB_INCLUDEDIR)/gobject/glib-types.h \
                 gir/glib-2.0.c
 if HAVE_GIO_UNIX