CLI backend: fix user-data

[rukai]

The user-data field is kind of cursed and will accept plaintext or base64 encoded plaintext which it automatically detects somehow.

However sometimes this automatic detection does not occur and the user-data remains as undecoded base64 and I cannot find any specification of what the base64 format needs to look like for it to automatically decode it.

So, to avoid this issue I am just directly passing in the user-data without base64 encoding.
And come to think of it, its just simpler all around if we dont have to encode as base64.