Revert redirect update stderr.

tester.py

@@ -123,7 +123,7 @@ class Tester():
         if '-n' not in args:
             tester_path = os.path.join(root_dir, os.path.basename(__file__))
             mtime = os.path.getmtime(tester_path)
-            subprocess.call(['python3', 'update_envsetup.py'], stderr=subprocess.STDOUT)
+            subprocess.call(['python3', 'update_envsetup.py'])
             if mtime != os.path.getmtime(tester_path):
                 log('The script has changed, restarting it...')
                 os.execl('/bin/python3', 'python3', tester_path, '-n', *args)