remove unnecessary shapefile archives

Dockerfile

@@ -126,7 +126,8 @@ RUN mkdir -p /home/renderer/src \
  && rm -rf .git \
  && npm install -g carto@0.18.2 \
  && carto project.mml > mapnik.xml \
- && scripts/get-shapefiles.py
+ && scripts/get-shapefiles.py \
+ && rm /home/renderer/src/openstreetmap-carto/data/*.zip
 
 # Configure renderd
 RUN sed -i 's/renderaccount/renderer/g' /usr/local/etc/renderd.conf \