[swell-foop] Do not forget to install appdata (bgo#793176)

[Robert Roth <robertroth src gnome org>]

commit bf6c1d1d12889fd4517839e92383055732b03a14
Author: Robert Roth <robert roth off gmail com>
Date:   Mon Feb 5 20:45:00 2018 +0200

    Do not forget to install appdata (bgo#793176)

 data/Makefile.am |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/data/Makefile.am b/data/Makefile.am
index cc03dfa..5b5bf80 100644
--- a/data/Makefile.am
+++ b/data/Makefile.am
@@ -16,6 +16,7 @@ $(desktop_DATA): $(desktop_in_files)
 
 appstream_in_files = swell-foop.appdata.xml.in
 appstream_XML = $(appstream_in_files:.xml.in=.xml)
+@APPSTREAM_XML_RULES@
 $(appstream_XML): $(appstream_in_files)
        $(AM_V_GEN)$(MSGFMT) --xml --template $< -d $(top_srcdir)/po -o $@