Bump json from 2.6.2 to 2.6.3

Bumps [json](https://github.com/flori/json) from 2.6.2 to 2.6.3.
- [Release notes](https://github.com/flori/json/releases)
- [Changelog](https://github.com/flori/json/blob/master/CHANGES.md)
- [Commits](https://github.com/flori/json/compare/v2.6.2...v2.6.3)

---
updated-dependencies:
- dependency-name: json
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -360,7 +360,7 @@ GEM
       thor (>= 0.14, < 2.0)
     jquery-ui-rails (4.2.1)
       railties (>= 3.2.16)
-    json (2.6.2)
+    json (2.6.3)
     json-jwt (1.16.0)
       activesupport (>= 4.2)
       aes_key_wrap