Bump express-session from 1.15.6 to 1.17.1

Bumps [express-session](https://github.com/expressjs/session) from 1.15.6 to 1.17.1.
- [Release notes](https://github.com/expressjs/session/releases)
- [Changelog](https://github.com/expressjs/session/blob/master/HISTORY.md)
- [Commits](expressjs/session@v1.15.6...v1.17.1)

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

Author: dependabot-preview[bot]

package-lock.json

@@ -56,7 +56,7 @@
     "deepmerge": "^3.2.0",
     "express": "4.16.4",
     "express-http-proxy": "^1.6.0",
-    "express-session": "1.15.6",
+    "express-session": "1.17.1",
     "history": "^4.7.2",
     "jsonminify": "0.4.1",
     "parse-github-url": "^1.0.2",