chore(deps): bump lodash from 4.17.15 to 4.17.21 in /server

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.15 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.15...4.17.21)

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

Author: dependabot[bot]

server/package-lock.json

@@ -20,7 +20,7 @@
   "dependencies": {
     "body-parser": "^1.18.3",
     "express": "^4.16.4",
-    "lodash": "^4.17.13",
+    "lodash": "^4.17.21",
     "nodemailer": "^4.7.0"
   }
 }