Multisig AID should not be allowed using more than one AID per agent

[pfeairheller]

Currently KERIA will allow you to create a group multisig AID using more than one AID from a single Agent. This breaks the mutlisig group AID and needs to be prevented with an error from the server.

[SmithSamuelM]

Eventually that should be allowed, but I guess this is because we only have a single .mhab instead of a list of mhabs in the group so that breaks haveing more that one local member.

[pfeairheller]

Yes, exactly. I've never seen the point because all keys from the same agent would be under the same key management security profile.