Bump axios from 0.20.0 to 0.21.2 in /frontend

Bumps [axios](https://github.com/axios/axios) from 0.20.0 to 0.21.2.
- [Release notes](https://github.com/axios/axios/releases)
- [Changelog](https://github.com/axios/axios/blob/v0.21.2/CHANGELOG.md)
- [Commits](axios/axios@v0.20.0...v0.21.2)

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

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

frontend/package.json

@@ -10,7 +10,7 @@
   "dependencies": {
     "@mdi/font": "^5.8.55",
     "ace-grammar": "github:foo123/ace-grammar#1.0.3",
-    "axios": "^0.20.0",
+    "axios": "^0.21.2",
     "bootstrap": "3.4.1",
     "bootstrap-vue": "^2.16.0",
     "brace": "^0.11.1",