__package_apt: update index cache, on installation, when it is older than one day

cdist/conf/type/__package_apt/gencode-remote

@@ -74,6 +74,11 @@ fi
 
 case "$state_should" in
     present)
+        cat << EOF
+if [ -f /var/cache/apt/pkgcache.bin ] && [ "\$( stat --format %Y /var/cache/apt/pkgcache.bin )" -lt "\$( date +%s -d '-1 day' )" ]
+then echo apt-get update > /dev/null 2>&1 || true
+fi
+EOF
         if [ -n "$version" ]; then
             name="${name}=${version}"
         fi