Bump log4js from 6.3.0 to 6.4.0

Bumps [log4js](https://github.com/log4js-node/log4js-node) from 6.3.0 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@v6.3.0...v6.4.0)

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

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Author: dependabot[bot]

package-lock.json

@@ -10,7 +10,7 @@
   ],
   "dependencies": {
     "typescript-logging": "^1.0.0",
-    "log4js": "6.3.0",
+    "log4js": "6.4.0",
     "tslog": "3.2.0"
   },
   "scripts": {