Merge branch '4.4'

* 4.4:
  fixed CS
  fixed CS
  fixed CS
  fixed CS
  Do not log or call the proxy function when the locale is the same
  Added missing required dependencies on psr/cache and psr/container in symfony/cache-contracts and symfony/service-contracts respectively.
  [HttpClient] fix closing debug stream prematurely
  [Mailer] made code more robust
  Restore compatibility with php 5.5
  fixed sender/recipients in SMTP Envelope
  collect called listeners information only once
  [HttpClient] add HttplugClient for compat with libs that need httplug v1 or v2
  [HttpKernel] Remove TestEventDispatcher.

composer.json

@@ -16,10 +16,10 @@
         }
     ],
     "require": {
-        "php": "^7.1.3"
+        "php": "^7.1.3",
+        "psr/container": "^1.0"
     },
     "suggest": {
-        "psr/container": "",
         "symfony/service-implementation": ""
     },
     "autoload": {