chore(deps): bump base64 from 0.21.7 to 0.22.1 in /stellar-lend (#570)

Bumps [base64](https://github.com/marshallpierce/rust-base64) from 0.21.7 to 0.22.1.
- [Changelog](https://github.com/marshallpierce/rust-base64/blob/master/RELEASE-NOTES.md)
- [Commits](marshallpierce/rust-base64@v0.21.7...v0.22.1)

---
updated-dependencies:
- dependency-name: base64
  dependency-version: 0.22.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

stellar-lend/Cargo.lock

@@ -31,7 +31,7 @@ tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 chrono = { version = "0.4", features = ["serde"] }
 
 # Base64 encoding/decoding
-base64 = "0.21"
+base64 = "0.22"
 
 # URL handling
 url = "2.5"