Update dependency psr/http-message to v2

Author: renovate[bot]

composer.json

@@ -10,7 +10,7 @@
     ],
     "require": {
         "php": "^7.4",
-        "psr/http-message": "^1.0.1",
+        "psr/http-message": "^1.0.1 || ^2.0.0",
         "react/http": "^1",
         "react/promise": "^2.8",
         "wyrihaximus/constants": "^1.5"