Add test case to cover non-empty auth entry

Signed-off-by: Jon Johnson <jonjohnson@google.com>

cli/config/configfile/file_test.go

@@ -389,9 +389,16 @@ func TestLoadFromReaderWithUsernamePassword(t *testing.T) {
 		Username: "user",
 		Password: "pass",
 	}
+
+	for _, tc := range []types.AuthConfig{
+		want,
+		types.AuthConfig{
+			Auth: encodeAuth(&want),
+		},
+	} {
 		cf := ConfigFile{
 			AuthConfigs: map[string]types.AuthConfig{
-			"example.com/foo": want,
+				"example.com/foo": tc,
 			},
 		}
 
@@ -407,6 +414,7 @@ func TestLoadFromReaderWithUsernamePassword(t *testing.T) {
 		assert.Check(t, is.DeepEqual(want.Username, got.Username))
 		assert.Check(t, is.DeepEqual(want.Password, got.Password))
 	}
+}
 
 func TestCheckKubernetesConfigurationRaiseAnErrorOnInvalidValue(t *testing.T) {
 	testCases := []struct {