Command to cleanup SSH known hosts

[juliogonzalez]

Today, running tests, I ended up with a VM using the same IP from an old VM, but of course a different SSH key.

That caused the following while onboarding:

Maybe this should be an mgradm command so the user doesn't need to manually run things on the container.

Something like:

mgradm ssh remove-know-host <IP/HOSTNAME>

If we do this change, then we should try to change that message to tell the user to use the command... not sure how complicated that will be, because that message comes directly from openssh.

[cbosdo]

Since this would touch files in the container, mgradm seems more suited than mgrctl.

[juliogonzalez]

Fixed on the description, I initially wrote mgrctl on one sentence, mgradm, by mistake :-)