Update dependency nodemailer to v6.9.9 [SECURITY] (#168)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package-lock.json

@@ -41,7 +41,7 @@
         "js-yaml": "4.1.0",
         "mathjs": "^11.3.3",
         "node-cron": "^3.0.2",
-        "nodemailer": "6.7.5",
+        "nodemailer": "6.9.9",
         "nodemon": "^2.0.20",
         "pg": "8.7.3",
         "textversionjs": "1.1.3",