[recipes] Avoid an assertion failure on fresh installs

[Matthias Clasen <matthiasc src gnome org>]

commit 1a3414356a13fd0603425b15619ba585695f714e
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Feb 13 18:54:18 2017 -0500

    Avoid an assertion failure on fresh installs
    
    When using the my chef information dialog on a fresh install,
    we end up in a situation where old == NULL. Don't assert that
    it isn't.

 src/gr-recipe-store.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/gr-recipe-store.c b/src/gr-recipe-store.c
index d183986..f04aa3d 100644
--- a/src/gr-recipe-store.c
+++ b/src/gr-recipe-store.c
@@ -1342,7 +1342,7 @@ gr_recipe_store_update_chef (GrRecipeStore  *self,
         }
 
         old = g_hash_table_lookup (self->chefs, old_id);
-        g_assert (chef == old);
+        g_assert (old == NULL || chef == old);
 
         g_hash_table_remove (self->chefs, old_id);
         g_hash_table_insert (self->chefs, g_strdup (id), g_object_ref (chef));