[NEL] Skip using SSH for localhost

[mxinO]

Is your feature request related to a problem? Please describe.
I work in the login node of a slurm cluster, the nel will force to use ssh with a hostname, but that won't work for MFA clusters which require manual verification even with ssh localhost. So I suggest the nel can run commands without ssh if localhost is specified.

Describe the solution you'd like
Run commands without ssh if localhost is specified.

Describe alternatives you've considered
Directly run without using the launcher.

[marta-sd]

Thanks for reporting @mxinO , this is not our usual setup (ie we usually run from our laptops or workstation) so we missed this corner-case. Let me add the ticket to our backlog 👍