Merge branch '4.4' into 5.0

* 4.4:
  [Security/Http] fix merge
  [ErrorHandler] fix setting $trace to null in FatalError

Author: nicolas-grekas

Error/FatalError.php

@@ -72,9 +72,11 @@ public function __construct(string $message, int $code, array $error, int $trace
             'line' => $error['line'],
             'trace' => $trace,
         ] as $property => $value) {
-            $refl = new \ReflectionProperty(\Error::class, $property);
-            $refl->setAccessible(true);
-            $refl->setValue($this, $value);
+            if (null !== $value) {
+                $refl = new \ReflectionProperty(\Error::class, $property);
+                $refl->setAccessible(true);
+                $refl->setValue($this, $value);
+            }
         }
     }