[network-manager-libreswan] build: fix make distcheck

[Lubomir Rintel <lkundrak src gnome org>]

commit 739f8c8de4ea601101f6b83e0a19314a5cf96497
Author: Lubomir Rintel <lkundrak v3 sk>
Date:   Mon Nov 16 17:27:19 2015 +0100

    build: fix make distcheck

 src/Makefile.am |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/src/Makefile.am b/src/Makefile.am
index c326cbe..b3a8d0a 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -65,4 +65,6 @@ show_xfrm_LDADD = $(LIBNL_LIBS) $(GLIB_LIBS)
 
 BUILT_SOURCES = nm-libreswan-helper-service-dbus.h nm-libreswan-helper-service-dbus.c
 
-CLEANFILES = *~
+CLEANFILES = *~ $(BUILT_SOURCES)
+
+EXTRA_DIST = nm-libreswan-helper-service.xml