Bump nodemailer from 6.4.11 to 6.4.16 in /server

Bumps [nodemailer](https://github.com/nodemailer/nodemailer) from 6.4.11 to 6.4.16.
- [Release notes](https://github.com/nodemailer/nodemailer/releases)
- [Changelog](https://github.com/nodemailer/nodemailer/blob/master/CHANGELOG.md)
- [Commits](https://github.com/nodemailer/nodemailer/compare/v6.4.11...v6.4.16)

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

server/package-lock.json

@@ -1043,9 +1043,9 @@
       }
     },
     "nodemailer": {
-      "version": "6.4.11",
-      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-6.4.11.tgz",
-      "integrity": "sha512-BVZBDi+aJV4O38rxsUh164Dk1NCqgh6Cm0rQSb9SK/DHGll/DrCMnycVDD7msJgZCnmVa8ASo8EZzR7jsgTukQ=="
+      "version": "6.4.16",
+      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-6.4.16.tgz",
+      "integrity": "sha512-68K0LgZ6hmZ7PVmwL78gzNdjpj5viqBdFqKrTtr9bZbJYj6BRj5W6WGkxXrEnUl3Co3CBXi3CZBUlpV/foGnOQ=="
     },
     "nopt": {
       "version": "3.0.6",