build(deps): bump passport from 0.4.1 to 0.6.0 in /backend

Bumps [passport](https://github.com/jaredhanson/passport) from 0.4.1 to 0.6.0.
- [Changelog](https://github.com/jaredhanson/passport/blob/master/CHANGELOG.md)
- [Commits](https://github.com/jaredhanson/passport/compare/v0.4.1...v0.6.0)

---
updated-dependencies:
- dependency-name: passport
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

backend/package.json

@@ -56,7 +56,7 @@
     "multer": "^1.4.3",
     "mysql": "^2.16.0",
     "parse-color": "^1.0.0",
-    "passport": "^0.4.0",
+    "passport": "^0.6.0",
     "passport-custom": "^1.0.5",
     "passport-oauth2": "^1.6.1",
     "pkg-up": "^3.1.0",