Bump express from 4.17.1 to 4.17.3

Bumps [express](https://github.com/expressjs/express) from 4.17.1 to 4.17.3.
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/master/History.md)
- [Commits](https://github.com/expressjs/express/compare/4.17.1...4.17.3)

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

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

monitor/package.json

@@ -17,7 +17,7 @@
     "bignumber.js": "^9.0.1",
     "cors": "^2.8.5",
     "dotenv": "^5.0.1",
-    "express": "^4.16.3",
+    "express": "^4.17.3",
     "node-fetch": "^2.1.2",
     "web3": "^1.3.0"
   },