Another exit when disk space can't be determined (eth-educators#1602)

ethd

@@ -48,7 +48,7 @@ determine_sudo() {
             echo "The Docker daemon is not running. Please check Docker installation."
             echo "\"sudo systemctl status docker\" and \"sudo journalctl -fu docker\" will be helpful."
             echo "Aborting."
-            exit 1
+            exit 130
         fi
     fi
     set -e
@@ -993,6 +993,7 @@ update() {
     if ! [[ "${__free_space}" =~ $re ]] ; then
         echo "Unable to determine free disk space. This is likely a bug."
         echo "df reports $(df -P "${__docker_dir}") and __free_space is ${__free_space}"
+        exit 130
     elif [ "${__free_space}" -lt 1048576 ]; then
         echo "You have less than 1 GiB of space left on ${__docker_dir}."
         echo "Aborting, as an update is not safe."