Update .gitlab-ci.yml

.gitlab-ci.yml

-image: maven:3.6.3-jdk-8
+image: bellsoft/liberica-openjdk-debian:8u
 
 
 build:
     script:
         - apt-get update
-        - apt-get install -y --no-install-recommends openjfx
+        - apt-get install -y --no-install-recommends maven
         - mvn package -B
         
 release: