title: didUpdateValueForCharacteristic not getting called on a reconnect
body: <p>Using CoreBluetooth, I can connect to a new device, get services and characteristics, and receive updates for characteristics.  </p>
  
  <p>When I reconnect to a bonded device that has its client characteristic configuration descriptor written, I expected my peripheral delegate's didUpdateValueForCharacteristic to be called as soon as I connect to the device and set up my peripheral delegate.  This should happen according to the Bluetooth standard, but is not happening. Am I missing something or is this an iOS bug? </p>
  
  <p>Note that it does get called if I do a setNotifyValue:forCharacteristic.</p>