Removed NSData

NSData autoclass is not used in the current implementation. Its prior purpose was to send client ID data, but its usage was deemed unnecessary, and replaced with a function that takes a string as a parameter to send the client's ID.

plyer/platforms/ios/voip.py

@@ -22,7 +22,6 @@
 AVAudioFormat = autoclass("AVAudioFormat")
 VoipMachine = autoclass('Voip')
 AVAudioSession = autoclass("AVAudioSession")
-NSData = autoclass('NSData')
 NSError = autoclass("NSError")
 
 class iOSVoip(Voip):
@@ -189,4 +188,4 @@ def _end_call(self):
             Logger.info("VOIP: Call ended")
 
 def instance():
-    return iOSVoip()
+    return iOSVoip()