Temporarily disable SSL verification

gitlab-ci/latex.yml

 compile_latex:
   image: aergus/latex # the docker image by aergus https://hub.docker.com/r/aergus/latex/
   stage: build
+  variables:
+    GIT_SSL_NO_VERIFY: "true"
   before_script:
     - git submodule sync
     - git submodule update --init --remote