Travis: try another work around

The previous hack got us to see that the error was a write error to
stdout and based on
https://github.com/travis-ci/travis-ci/issues/4704#issuecomment-321777557
setting filter_secrets: false will work around that issue.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

.travis.yml

@@ -51,6 +51,7 @@ matrix:
       # Currently hard coded to arm
       os: linux
       language: c++
+      filter_secrets: false
       services:
           - docker
 # TODO: caching