key import with an empty password doesn't work

[ConnorRigby]

i did a mix nerves_hub.key import keyname /path/to/key.pub /path/to/key.priv and just mashed enter until it errored out, but even tho there was an error, it actually imported the key. when i did mix nerves_hub.key delete and mashed enter it gave an error, and didn't delete it.

I'm fine with not allowing empty password, but right now it gets left in a limbo state if you try this.

[ConnorRigby]

oh also, my key now exists in nerves-hub, but i can't delete it from the frontend