Update humanmade/aws-xray requirement from ~1.3.8 to ~1.3.9

Updates the requirements on [humanmade/aws-xray](https://github.com/humanmade/aws-xray) to permit the latest version.
- [Release notes](https://github.com/humanmade/aws-xray/releases)
- [Changelog](https://github.com/humanmade/aws-xray/blob/master/CHANGELOG.md)
- [Commits](humanmade/aws-xray@1.3.8...1.3.9)

---
updated-dependencies:
- dependency-name: humanmade/aws-xray
  dependency-version: 1.3.9
  dependency-type: direct:production
...

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

Author: dependabot[bot]

composer.json

@@ -30,7 +30,7 @@
 	"require": {
 		"php": ">=7.1",
 		"humanmade/wp-redis-predis-client": "0.1.2",
-		"humanmade/aws-xray": "~1.3.8",
+		"humanmade/aws-xray": "~1.3.9",
 		"humanmade/s3-uploads": "^3.0.11",
 		"humanmade/cavalcade": "^2.0.2",
 		"pantheon-systems/wp-redis": "1.4.6",