[PATCH] TestMaskSecretKeys: add more test-cases

[PATCH] TestMaskSecretKeys: add more test-cases

Add tests for

- case-insensitive matching of fields
- recursive masking

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit db5f811216e70bcb4a10e477c1558d6c68f618c5)
Signed-off-by: Tibor Vass <tibor@docker.com>
(cherry picked from commit 18dac2cf32faeaada3bd4e8e2bffa576ad4329fe)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Origin: upstream, https://github.com/docker/engine/pull/298

Gbp-Pq: Name cve-2019-13509-01-TestMaskSecretKeys-add-more-test-cases.patch