Merge branch '5.0' into 5.1

* 5.0:
  minor #37121 [Contracts] Add missing "extra.thanks" entries in composer.json (nicolas-grekas)
  [Process] Fix Permission Denied error when writing sf_proc_00 lock files on Windows
  fix handling null as empty data
  No need to create an issue when creating a PR
  Use ">=" for the "php" requirement
  [HttpClient] Fix promise behavior in HttplugClient
  [Console] Fixes question input encoding on Windows

composer.json

@@ -28,6 +28,10 @@
     "extra": {
         "branch-alias": {
             "dev-master": "2.1-dev"
+        },
+        "thanks": {
+            "name": "symfony/contracts",
+            "url": "https://github.com/symfony/contracts"
         }
     }
 }