Fix test broken by stricter validation in new version of base64 crate
Fix test broken by stricter validation in new version of base64 crate

Previously the string "base64" would be successfully decoded, but no longer.
Replacing it with a legal base64-encoded string fixes things.

Signed-off-by: Jon Bauman <e6c6a4db54ad11b4de69fed67139594b59f3444f@users.noreply.github.com>

rsertelon/habitat,habitat-sh/habitat,habitat-sh/habitat,rsertelon/habitat,rsertelon/habitat,habitat-sh/habitat,rsertelon/habitat,rsertelon/habitat,rsertelon/habitat,habitat-sh/habitat,habitat-sh/habitat,rsertelon/habitat,habitat-sh/habitat,habitat-sh/habitat,habitat-sh/habitat