Install ca-certificates and use the CA file as we're not built against OpenSSL

.gitlab-ci.yml

@@ -6,7 +6,7 @@ publish:
   script:
     - apt-get update
     - apt-get dist-upgrade -y
-    - apt-get install -y lftp
-    - echo 'set ssl:ca-path "/etc/ssl/certs"' >> /etc/lftp.conf
+    - apt-get install -y lftp ca-certificates
+    - echo 'set ssl:ca-file "/etc/ssl/certs/ca-certificates.crt"' >> /etc/lftp.conf
     - lftp -e "mirror --exclude ^\.git.* --exclude \.gitlab-ci.yaml -eRv  $CI_PROJECT_DIR builds/$CI_BUILD_REF_NAME; quit;" https://$CREDENTIALS/