Update Dockerfile

I fancy-clicked @bertsky's change suggestion, which duplicated some labels. Now fancy-clicking the fix, fingers crossed...

Author: mikegerber

Dockerfile

@@ -2,15 +2,11 @@ ARG DOCKER_BASE_IMAGE
 FROM $DOCKER_BASE_IMAGE
 ARG VCS_REF
 ARG BUILD_DATE
-LABEL \
 LABEL \
     maintainer="https://github.com/qurator-spk/dinglehopper/issues" \
     org.label-schema.vcs-ref=$VCS_REF \
     org.label-schema.vcs-url="https://github.com/qurator-spk/dinglehopper" \
     org.label-schema.build-date=$BUILD_DATE
-    org.label-schema.vcs-ref=$VCS_REF \
-    org.label-schema.vcs-url="https://github.com/qurator-spk/dinglehopper" \
-    org.label-schema.build-date=$BUILD_DATE
 
 WORKDIR /build/dinglehopper
 COPY pyproject.toml .