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](expressjs/express@4.17.1...4.17.3)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -25,7 +25,7 @@
     "dotenv": "6.0.0",
     "dotenv-expand": "4.2.0",
     "easymde": "^2.18.0",
-    "express": "^4.16.4",
+    "express": "^4.17.3",
     "fflate": "^0.7.4",
     "file-loader": "2.0.0",
     "filestack-js": "^3.20.0",