[iOS] ReactNativePageView.m line 154 crash

## Environment

iOS
```
"react-native-pager-view": "^5.4.9",
"react-native": "0.66.1",
```

## Description

We get a number of crash reports in crashlytics about next issue:
```
ReactNativePageView.m line 154
-[ReactNativePageView setupInitialController]
```

```
Fatal Exception: NSRangeException
*** -[__NSArrayM objectAtIndexedSubscript:]: index 18446744073709551615 beyond bounds [0 .. 0]
Fatal Exception: NSRangeException
0 CoreFoundation 0x9270c __exceptionPreprocess
1 libobjc.A.dylib 0x14f04 objc_exception_throw
2 CoreFoundation 0x18c984 -[__NSCFString characterAtIndex:].cold.1
3 CoreFoundation 0x354c8 __NSDictionaryMutablePlaceholder
4 APPNAME 0x3c513c -[ReactNativePageView setupInitialController] + 154 (ReactNativePageView.m:154)
5 APPNAME 0x3c4884 -[ReactNativePageView didMoveToWindow] + 92 (ReactNativePageView.m:92)
6 UIKitCore 0x29f760 -[UIView(Internal) _didMoveFromWindow:toWindow:]
7 UIKitCore 0x29f244 -[UIView(Internal) _didMoveFromWindow:toWindow:]
8 UIKitCore 0x29f244 -[UIView(Internal) _didMoveFromWindow:toWindow:]
9 UIKitCore 0x29f244 -[UIView(Internal) _didMoveFromWindow:toWindow:]
10 UIKitCore 0x29f244 -[UIView(Internal) _didMoveFromWindow:toWindow:]
11 UIKitCore 0x1cbf00 __45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke
12 UIKitCore 0x257adc -[UIView(Hierarchy) _postMovedFromSuperview:]
13 UIKitCore 0x17a20c -[UIView(Internal) _addSubview:positioned:relativeTo:]
14 UIKitCore 0x25f6c4 -[UITransitionView transition:fromView:toView:removeFromView:]
15 UIKitCore 0x2bf838 -[UIViewControllerBuiltinTransitionViewAnimator animateTransition:]
16 UIKitCore 0x48a170 ___UIViewControllerTransitioningRunCustomTransition_block_invoke_2
17 UIKitCore 0x2c88f0 +[UIKeyboardSceneDelegate _pinInputViewsForKeyboardSceneDelegate:onBehalfOfResponder:duringBlock:]
18 UIKitCore 0x33b35c ___UIViewControllerTransitioningRunCustomTransition_block_invoke.641
19 UIKitCore 0x3c1d58 +[UIView(Animation) _setAlongsideAnimations:toRunByEndOfBlock:]
20 UIKitCore 0x265698 _UIViewControllerTransitioningRunCustomTransition
21 UIKitCore 0x88fd20 __56-[UIPresentationController runTransitionForCurrentState]_block_invoke.401
22 UIKitCore 0x30c4cc -[_UIAfterCACommitBlock run]
23 UIKitCore 0x227b8c -[_UIAfterCACommitQueue flush]
24 UIKitCore 0x156518 _runAfterCACommitDeferredBlocks
25 UIKitCore 0x156be4 _cleanUpAfterCAFlushAndRunDeferredBlocks
26 UIKitCore 0x156db0 _afterCACommitHandler
27 CoreFoundation 0x3e21c __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__
28 CoreFoundation 0xf454 __CFRunLoopDoObservers
29 CoreFoundation 0xa9dc __CFRunLoopRun
30 CoreFoundation 0x1dc30 CFRunLoopRunSpecific
31 GraphicsServices 0x1988 GSEventRunModal
32 UIKitCore 0x4e5c50 -[UIApplication _run]
33 UIKitCore 0x27f3d0 UIApplicationMain
34 APPNAME 0x7044 main + 14 (main.m:14)
35 ??? 0x1058ec3d0 (Missing)
```
Have anybody experienced something similar and can help identifying the problem of the crash?

Inizia da ReactNativePageView.m alla riga 154 e segui setupInitialController a partire da didMoveToWindow. Riproduci la NSRangeException con react-native-pager-view 5.4.9 e React Native 0.66.1, quindi circoscrivi lo stato iniziale del controller che causa il fallimento. Il lavoro è completato quando la causa del crash è riproducibile e viene fornita una correzione verificata o dettagli chiari per la riproduzione.

Scritto dal modello di indicizzazione a partire dal testo della issue.