Update appendix.rst

Found that if docker.socket is also stopped, the service won't unexpectedly start backup.

appendix.rst

@@ -58,16 +58,17 @@ Disable services and reboot:
 Make sure docker containers are stopped:
 ::
 
-    sudo su -c "systemctl stop docker"
+    sudo su -c "systemctl stop docker docker.socket"
     sudo docker ps
 
 If there are any remaining docker processes, stop them (replacing ``$CONT_ID`` with the actual ID):
 ::
 
     sudo docker stop $CONT_ID
 
-    This can be done in one command using:
-    sudo docker ps | awk '!/CONTAINER/ { system("sudo docker stop " $1 ) }'
+This can also be done in one command:
+::
+    sudo docker ps | awk '!/CONTAINER/&& !// { system("sudo docker stop " $1 ) }'
 
 Unmount /nsm:
 ::