Fix link to installation instructions

Fix #17872:

> The script at https://get.docker.com/ links to https://docs.docker.com/en/latest/installation/, which gives a 404 error. The correct link is https://docs.docker.com/engine/installation/.

Signed-off-by: Paolo G. Giarrusso <p.giarrusso@gmail.com>

hack/install.sh

@@ -439,7 +439,7 @@ do_install() {
 	  a package for Docker.  Please visit the following URL for more detailed
 	  installation instructions:
 
-	    https://docs.docker.com/en/latest/installation/
+	    https://docs.docker.com/engine/installation/
 
 	EOF
 	exit 1