Install gnutls28 before running build script

.gitlab-ci.yml

@@ -1,11 +1,14 @@
+image: 'debian:stable'
 stages:
   - build
 
+before_script:
+  - apt update && apt install -y make wget git emacs sudo gnutls28
+
 .build:
   image: debian:stable-slim
   stage: build
   before_script:
-    - apt update && apt install -y make wget git emacs sudo
     - git clone -b $CI_COMMIT_REF_NAME https://gitlab.com/FG42/FG42 ~/.fg42/ && cd ~/.fg42/ && make install &&
   script:
     - cd ~/.fg42/ && fg42 -nw --script build.el