contrib/install.sh: remove pull of hello-world

This removes the pull of the hello-world image from install.sh to
address privacy concerns.

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)

hack/install.sh

@@ -85,7 +85,7 @@ case "$lsb_dist" in
 		if command_exists docker && [ -e /var/run/docker.sock ]; then
 			(
 				set -x
-				$sh_c 'docker run --rm hello-world'
+				$sh_c 'docker version'
 			) || true
 		fi
 		your_user=your-user
@@ -162,7 +162,7 @@ case "$lsb_dist" in
 		if command_exists docker && [ -e /var/run/docker.sock ]; then
 			(
 				set -x
-				$sh_c 'docker run --rm hello-world'
+				$sh_c 'docker version'
 			) || true
 		fi
 		your_user=your-user