installer: move unzip to base image

scripts/installer.sh

@@ -70,12 +70,6 @@ fi
 apt remove -y gnome-shell || true
 apt -y autoremove || true
 
-# Only used for the cloudron-translation-update script
-if ! which unzip; then
-    echo "==> installer: installing unzip"
-    apt install -y unzip
-fi
-
 echo "==> installer: updating node"
 if [[ "$(node --version)" != "v10.18.1" ]]; then
     mkdir -p /usr/local/node-10.18.1