Fix TestBuildWithSession, TestBuildSquashParent using wrong daemon during test

These tests were spinning up a new daemon, but after the daemon was spun up,
the default test-daemon was used by the client.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 9a3911ced83331b6efe698528a4480bd5ff3d7a6)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

integration/build/build_session_test.go

@@ -27,7 +27,7 @@ func TestBuildWithSession(t *testing.T) {
 	d.StartWithBusybox(t)
 	defer d.Stop(t)
 
-	client := testEnv.APIClient()
+	client := d.NewClientT(t)
 
 	dockerfile := `
 		FROM busybox

integration/build/build_squash_test.go

@@ -26,7 +26,7 @@ func TestBuildSquashParent(t *testing.T) {
 	d.StartWithBusybox(t)
 	defer d.Stop(t)
 
-	client := testEnv.APIClient()
+	client := d.NewClientT(t)
 
 	dockerfile := `
 		FROM busybox