Merge branch '4.4'

* 4.4: (23 commits)
  [HttpFoundation] fix docblock
  [HttpKernel] Flatten "exception" controller argument if not typed
  Fix MySQL column type definition.
  Link the right file depending on the new version
  [Cache] Redis Tag Aware warn on wrong eviction policy
  [HttpClient] fix HttpClientDataCollector
  [HttpKernel] collect bundle classes, not paths
  [Config] fix id-generation for GlobResource
  [HttpKernel] dont check cache freshness more than once per process
  [Finder] Allow ssh2 stream wrapper for sftp
  [FrameworkBundle] fix wiring of httplug client
  add FrameworkBundle requirement
  [SecurityBundle] add tests with empty authenticator
  [Security] always check the token on non-lazy firewalls
  [DI] Use reproducible entropy to generate env placeholders
  [WebProfilerBundle] Require symfony/twig-bundle
  [Mailer] Add UPGRADE entry about the null transport DSN
  bumped Symfony version to 4.3.9
  updated VERSION for 4.3.8
  updated CHANGELOG for 4.3.8
  ...

Author: nicolas-grekas

DataCollector/HttpClientDataCollector.php

@@ -133,6 +133,7 @@ private function collectOnClient(TraceableHttpClient $client): array
 
             $debugInfo = array_diff_key($info, $baseInfo);
             $info = array_diff_key($info, $debugInfo) + ['debug_info' => $debugInfo];
+            unset($traces[$i]['info']); // break PHP reference used by TraceableHttpClient
             $traces[$i]['info'] = $this->cloneVar($info);
             $traces[$i]['options'] = $this->cloneVar($trace['options']);
         }