[recipes] Don't validate screenshot urls

[Matthias Clasen <matthiasc src gnome org>]

commit da58c288d1339e85e782eb322de7e64dbfa66106
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Mar 2 16:49:20 2017 -0500

    Don't validate screenshot urls
    
    Network access is problematic in some build systems.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=779495

 data/Makefile.am |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/data/Makefile.am b/data/Makefile.am
index 95e8a0c..4959294 100644
--- a/data/Makefile.am
+++ b/data/Makefile.am
@@ -279,4 +279,4 @@ dist_searchprovider_DATA = org.gnome.Recipes-search-provider.ini
 check: check-appstream
 
 check-appstream: appdata/org.gnome.Recipes.appdata.xml
-       $(APPSTREAM_UTIL) validate-relax $<
+       $(APPSTREAM_UTIL) validate-relax --nonet $<