generic: disabled heimdal on the reference pkgsel

target/generic/pkgsel/99-reference.choice

@@ -2,7 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: target/generic/pkgsel/99-reference.choice
-# Copyright (C) 2006 - 2008 The OpenSDE Project
+# Copyright (C) 2006 - 2009 The OpenSDE Project
 #
 # More information can be found in the files COPYING and README.
 #
@@ -19,6 +19,7 @@ O attic/*
 O wip/*
 - icc
 - vmware
+O heimdal
 
 # some kernel patches which can't coexist
 # - vserver