Bump ioredis from 4.27.3 to 4.27.4

Bumps [ioredis](https://github.com/luin/ioredis) from 4.27.3 to 4.27.4.
- [Release notes](https://github.com/luin/ioredis/releases)
- [Changelog](https://github.com/luin/ioredis/blob/master/Changelog.md)
- [Commits](redis/ioredis@v4.27.3...v4.27.4)

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

package.json

@@ -31,7 +31,7 @@
     "browserify": "^17.0.0",
     "debug": "^4.3.1",
     "dog-names": "^2.0.0",
-    "ioredis": "^4.27.3",
+    "ioredis": "^4.27.4",
     "koa": "^2.13.1",
     "koa-router": "^10.0.0",
     "koa-static": "^5.0.0",