use explicit empty entrypoint

.gitlab-ci.yml

@@ -26,7 +26,9 @@ build:
       - "java_files/"
 
 ragdoc_build:
-  image: "git-st.inf.tu-dresden.de:4567/jastadd/ragdoc-builder"
+  image:
+    name: "git-st.inf.tu-dresden.de:4567/jastadd/ragdoc-builder"
+    entrypoint: [""]
   stage: ragdoc_build
   dependencies:
     - build
@@ -38,7 +40,9 @@ ragdoc_build:
       - "data/"
 
 ragdoc_view:
-  image: "git-st.inf.tu-dresden.de:4567/jastadd/ragdoc-view:relations"
+  image:
+    name: "git-st.inf.tu-dresden.de:4567/jastadd/ragdoc-view:relations"
+    entrypoint: [""]
   stage: ragdoc_view
   dependencies:
     - ragdoc_build