Update .gitlab-ci.yml: remove these ssh debug lines

.gitlab-ci.yml

-
 stages:
   - build
   - test
@@ -6,8 +5,6 @@ stages:
 build:
   stage: build
   script:
-    - eval `ssh-agent -s`
-    - ssh-add ~/.ssh/id_rsa.pub
     - ssh -vvv git@gitlab.inria.fr
     - git submodule init
     - git submodule update