The NEO promise that was introduced in nexedi/slapos@a3bb9a41
always fails with older NEO versions [1]. In order to not always have a
red monitoring state of our NEO cluster, this patch returns the promise
to the state before NEO specific promise was introduced.

[1] This promise checks NEO cluster state via 'print summary' command [2].
Old NEO doesn't know 'print summary' command. This command was only
introduced with nexedi/neoppod@e434c253.

[2] See nexedi/slapos.toolbox@2d69e8fb