Check in integration test that snapshots are listed before the index

As an exception prune is still allowed to load the index before
snapshots, as it uses exclusive locks. In case of problems with locking
it is also better to load snapshots created after loading the index, as
this will lead to a prune sanity check failure instead of a broken snapshot.

cmd/restic/integration_fuse_test.go

@@ -154,6 +154,8 @@ func TestMount(t *testing.T) {
 	}
 
 	env, cleanup := withTestEnvironment(t)
+	// must list snapshots more than once
+	env.gopts.backendTestHook = nil
 	defer cleanup()
 
 	testRunInit(t, env.gopts)
@@ -197,6 +199,8 @@ func TestMountSameTimestamps(t *testing.T) {
 	}
 
 	env, cleanup := withTestEnvironment(t)
+	// must list snapshots more than once
+	env.gopts.backendTestHook = nil
 	defer cleanup()
 
 	rtest.SetupTarTestFixture(t, env.base, filepath.Join("testdata", "repo-same-timestamps.tar.gz"))