Replace git ssh references with https ones

so gitlab knows what to do, hopefully

.gitlab-ci.yml

 image: registry.gitlab.tugraz.at/dbp/middleware/dbp-api/api-starter-bundle:v1
 
+before_script:
+  - "sed -i 's|git@gitlab.tugraz.at:|https://gitlab.tugraz.at/|g' composer.json composer.lock"
+
 variables:
   COMPOSER_CACHE_DIR: "$CI_PROJECT_DIR/_composer_cache"