Update fig/http-message-util requirement from ^1.1.2 to ^1.1.4

Updates the requirements on [fig/http-message-util](https://github.com/php-fig/http-message-util) to permit the latest version.
- [Release notes](https://github.com/php-fig/http-message-util/releases)
- [Changelog](https://github.com/php-fig/http-message-util/blob/master/CHANGELOG.md)
- [Commits](php-fig/http-message-util@1.1.2...1.1.4)

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

composer.json

@@ -29,7 +29,7 @@
   ],
   "require": {
     "php": "^7.2",
-    "fig/http-message-util": "^1.1.2",
+    "fig/http-message-util": "^1.1.4",
     "psr/http-factory": "^1.0",
     "psr/http-message": "^1.0",
     "ralouphie/getallheaders": "^3"