Fix flakiness in ECS E2E : wait when reaching nginx welcome page, sometimes stack is not fully up and we get 503 errors
Fix flakiness in ECS E2E : wait when reaching nginx welcome page, sometimes stack is not fully up and we get 503 errors

Signed-off-by: Guillaume Tardif <fdb6d90518c0d82cc6b9e4626ba807cce7a41bc7@docker.com>
docker/compose,docker/compose,docker/compose