Remove tap on ios destroy function

[ghsdh3409]

Error

• When the below error is raised, speech module can't work.
  • com.apple.coreaudio.avfaudio - required condition is false: nullptr == Tap()

Solution

• It always should remove tap on bus.
• https://stackoverflow.com/questions/41438219/terminating-app-due-to-uncaught-app-crashes-while-using-speech-kit-ios