new: [host] check if curl is already installed

This was needed in debian 10.

Signed-off-by: Valentin Lab <valentin.lab@kalysto.org>

precise/host/hooks/install.d/60-docker.sh

@@ -3,6 +3,9 @@
 need_restart=
 if ! type -p docker; then
     echo "Installing docker..."
+    type -p curl >dev/null ||
+        apt-get install -y curl </dev/null
+
     curl -sSL https://get.docker.io | sh
 fi