Update Manager.php

[marscoo]

fix for issue addressed on #213

[marscoo]

use this with following config in config/swoole_http.php

'server' => [
  ...
  'options' => [
    ...
    'task_enable_coroutine' => true,
  ]
]

[coveralls]

Coverage decreased (-0.08%) to 67.894% when pulling 2922c4a on marscoo:support-task_enable_coroutine-option into 22c775e on swooletw:master.