[Process] removed workaround as it seems to not work anymore after the recent changes

src/Symfony/Component/Process/Process.php

@@ -104,14 +104,7 @@ class Process
             }
         };
 
-        // Workaround for http://bugs.php.net/bug.php?id=51800
-        if (strstr(PHP_OS, 'WIN')) {
-            $stderrPipeMode = 'a';
-        } else {
-            $stderrPipeMode = 'w';
-        }
-
-        $descriptors = array(array('pipe', 'r'), array('pipe', 'w'), array('pipe', $stderrPipeMode));
+        $descriptors = array(array('pipe', 'r'), array('pipe', 'w'), array('pipe', 'w'));
 
         $process = proc_open($this->commandline, $descriptors, $pipes, $this->cwd, $this->env, $this->options);