"Pubkey already added to Ionic." treated as OK even when adding from different account

[imhoffd]

This is only really an issue for a single person with multiple appflow accounts.

Repro:

1. Log into account A and add an ssh key (ionic ssh add)
2. Re-adding it from account A should be OK
3. Log into account B and add the same key
4. Re-adding it from account B should be an error (the "already added" message is incorrect for their account)

https://github.com/ionic-team/ionic-cli/blob/develop/packages/ionic/src/commands/ssh/add.ts#L90