Bump next from 9.1.4 to 9.3.2 in /admin

Bumps [next](https://github.com/zeit/next.js) from 9.1.4 to 9.3.2.
- [Release notes](https://github.com/zeit/next.js/releases)
- [Commits](https://github.com/zeit/next.js/compare/v9.1.4...v9.3.2)

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

admin/package.json

@@ -9,7 +9,7 @@
     "export": "next build && next export -o build"
   },
   "dependencies": {
-    "next": "9.1.4",
+    "next": "9.3.2",
     "react": "16.12.0",
     "react-dom": "16.12.0"
   }