fix: unjank the demo (#85)

Co-authored-by: tahahawa <tahahawa@gmail.com>
Reviewed-on: NationTech/harmony#85
Reviewed-by: wjro <wrolleman@nationtech.io>

examples/rust/Cargo.toml

@@ -12,3 +12,4 @@ tokio = { workspace = true }
 log = { workspace = true }
 env_logger = { workspace = true }
 url = { workspace = true }
+base64.workspace = true