iOS app crashes if access to the camera is disallowed after the fact

[ookamisensei]

Here's the scenario:
-start the plugin, and given that you've configured your iOS app correctly, it'll start the camera.

• go into the phone's Setting, to your app's settings and flip the Camera off.
• go back into your app and try to start the qr scanning again. The app instantly crashes:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[AVCaptureSession addInput:] Can't add a nil AVCaptureInput'
*** First throw call stack:
(0x199a2d86c 0x1aea48c50 0x1b3dbfba4 0x100992208 0x100991dc4 0x100992a78 0x100a9deac 0x100a99400 0x100daea60 0x100abfd7c 0x100dc9070 0x100d631d4 0x100d659fc 0x1999a9fa0 0x1999a9ba0 0x1999a8ffc 0x1999a2ee4 0x1999a221c 0x1b156e784 0x19c3e2ee8 0x19c3e875c 0x1004f76d0 0x1996626b0)
libc++abi.dylib: terminating with uncaught exception of type NSException
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
    frame #0: 0x00000001c7982414 libsystem_kernel.dylib`__pthread_kill + 8
libsystem_kernel.dylib`__pthread_kill:
->  0x1c7982414 <+8>:  b.lo   0x1c7982434               ; <+40>
    0x1c7982418 <+12>: pacibsp 
    0x1c798241c <+16>: stp    x29, x30, [sp, #-0x10]!
    0x1c7982420 <+20>: mov    x29, sp
Target 0: (Runner) stopped.
Lost connection to device.