Bump redis from 4.6.10 to 4.6.13 in /server

Bumps [redis](https://github.com/redis/node-redis) from 4.6.10 to 4.6.13.
- [Release notes](https://github.com/redis/node-redis/releases)
- [Changelog](https://github.com/redis/node-redis/blob/master/CHANGELOG.md)
- [Commits](https://github.com/redis/node-redis/compare/redis@4.6.10...redis@4.6.13)

---
updated-dependencies:
- dependency-name: redis
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

server/package.json

@@ -20,7 +20,7 @@
     "path": "^0.12.7",
     "pg": "^8.8.0",
     "pg-hstore": "^2.3.4",
-    "redis": "^4.6.10",
+    "redis": "^4.6.13",
     "sequelize": "^6.35.2",
     "winston": "^3.11.0",
     "ws": "^8.8.1"