chore(deps-dev): bump log4js from 6.2.1 to 6.4.0

Bumps [log4js](https://github.com/log4js-node/log4js-node) from 6.2.1 to 6.4.0.
- [Release notes](https://github.com/log4js-node/log4js-node/releases)
- [Changelog](https://github.com/log4js-node/log4js-node/blob/master/CHANGELOG.md)
- [Commits](log4js-node/log4js-node@v6.2.1...v6.4.0)

---
updated-dependencies:
- dependency-name: log4js
  dependency-type: direct:development
...

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

Author: dependabot[bot]

package-lock.json

@@ -38,7 +38,7 @@
         "class-validator": "^0.12.2",
         "config": "^3.2",
         "js-yaml": "^3.13",
-        "log4js": "^6.2",
+        "log4js": "^6.4",
         "passport": "~0.4.0",
         "reflect-metadata": "~0.1.13",
         "rxjs": "^6.5"
@@ -60,7 +60,7 @@
         "class-validator": "^0.12.2",
         "config": "^3.2",
         "js-yaml": "^3.13",
-        "log4js": "^6.2",
+        "log4js": "^6.4",
         "passport": "~0.4.0",
         "reflect-metadata": "~0.1.13",
         "rxjs": "^6.5",