[dconf] tests: Add an assertion

[Matthias Clasen <matthiasc src gnome org>]

commit 7c0beccf286a1dbd396fda7d40b438598a6ce7f4
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Jul 17 17:18:29 2015 -0400

    tests: Add an assertion
    
    This makes coverity happy. It noticed that we check source for
    being non-NULL every other case but not here.

 tests/engine.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/tests/engine.c b/tests/engine.c
index 174417d..09e89c2 100644
--- a/tests/engine.c
+++ b/tests/engine.c
@@ -505,6 +505,7 @@ test_service_source (void)
    */
   dconf_engine_source_free (source);
   source = dconf_engine_source_new ("service-db:shm/nil");
+  g_assert (source != NULL);
   reopened = dconf_engine_source_refresh (source);
   g_assert (reopened);