strongswan: fixed to use the linux kernel headers installed by the linux-header package

security/strongswan/strongswan.conf

@@ -2,7 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: package/.../strongswan/strongswan.conf
-# Copyright (C) 2010 - 2011 The OpenSDE Project
+# Copyright (C) 2010 - 2013 The OpenSDE Project
 # Copyright (C) 2004 - 2006 The T2 SDE Project
 #
 # More information can be found in the files COPYING and README.
@@ -23,6 +23,11 @@ fi
 export ACLOCAL_FLAGS="-I m4/config/"
 autogen=1
 
+# use the installed linux headers
+if pkginstalled -f linux-header; then
+	var_append extraconfopt ' ' "--with-linux-headers=$( pkgprefix -r includedir linux-header )"
+fi
+
 # checking if we can enable CRL fetching using HTTP
 if pkginstalled curl; then
 	var_append extraconfopt ' ' "--enable-curl"