修复拍照偶现闪退问题

    private func setupCamera() {
        guard let backCamera = getCamera(position: .back) else { return }
        guard let input = try? AVCaptureDeviceInput(device: backCamera) else { return }

如果此代码执行了return, 此时movieFileOutput和imageOutput为空, 强制解包会造成闪退

Thread 0 name:
Thread 0 Crashed:
0   MIGO Live                       0x0000000103336934 Swift runtime failure: Unexpectedly found nil while implicitly unwrapping an Optional value + 0 (ZLCustomCamera.swift:0)
1   MIGO Live                       0x0000000103336934 ZLCustomCamera.takePicture() + 740 (ZLCustomCamera.swift:752)
2   MIGO Live                       0x0000000103336680 ZLCustomCamera.takePicture() + 48 (ZLCustomCamera.swift:748)
3   MIGO Live                       0x000000010333697c @objc ZLCustomCamera.takePicture() + 28 (<compiler-generated>:0)
4   UIKitCore                       0x000000018b297470 -[UIGestureRecognizerTarget _sendActionWithGestureRecognizer:] + 128 (UIPerformVoidSelector.h:48)
5   UIKitCore                       0x000000018b6050bc _UIGestureRecognizerSendTargetActions + 92 (UIGestureRecognizer.m:1527)
6   UIKitCore                       0x000000018b37ec30 _UIGestureRecognizerSendActions + 272 (UIGestureRecognizer.m:1566)
7   UIKitCore                       0x000000018b25f60c -[UIGestureRecognizer _updateGestureForActiveEvents] + 484 (UIGestureRecognizer.m:0)
8   UIKitCore                       0x000000018b30b560 _UIGestureEnvironmentUpdate + 2436 (UIGestureEnvironment.m:198)
9   UIKitCore                       0x000000018bb9293c -[UIGestureEnvironment _deliverEvent:toGestureRecognizers:usingBlock:] + 288 (UIGestureEnvironment.m:1376)
10  UIKitCore                       0x000000018b2d0020 -[UIGestureEnvironment _updateForEvent:window:] + 188 (UIGestureEnvironment.m:1345)
11  UIKitCore                       0x000000018b2d4978 -[UIWindow sendEvent:] + 3268 (UIWindow.m:3472)
12  UIKitCore                       0x000000018b2d3c48 -[UIApplication sendEvent:] + 672 (UIApplication.m:12548)
13  UIKitCore                       0x000000018b2d3304 __dispatchPreprocessedEventFromEventQueue + 7084 (UIEventDispatcher.m:2417)
14  UIKitCore                       0x000000018b31b018 __processEventQueue + 5632 (UIEventDispatcher.m:2726)
15  UIKitCore                       0x000000018b62355c __eventFetcherSourceCallback + 224 (UIEventDispatcher.m:2798)
16  CoreFoundation                  0x00000001890d9f34 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 (CFRunLoop.c:1957)
17  CoreFoundation                  0x00000001890e630c __CFRunLoopDoSource0 + 176 (CFRunLoop.c:2001)
18  CoreFoundation                  0x000000018906a1d0 __CFRunLoopDoSources0 + 244 (CFRunLoop.c:2038)
19  CoreFoundation                  0x000000018907fb8c __CFRunLoopRun + 836 (CFRunLoop.c:2953)
20  CoreFoundation                  0x0000000189084ec0 CFRunLoopRunSpecific + 612 (CFRunLoop.c:3418)
21  GraphicsServices                0x00000001c30db368 GSEventRunModal + 164 (GSEvent.c:2196)
22  UIKitCore                       0x000000018b57a86c -[UIApplication _run] + 888 (UIApplication.m:3754)
23  UIKitCore                       0x000000018b57a4d0 UIApplicationMain + 340 (UIApplication.m:5344)
24  MIGO Live                       0x00000001028c94b4 main + 80 (main.m:14)
25  dyld                            0x00000001a78a6960 start + 2528 (dyldMain.cpp:1170)

longitachi / ZLPhotoBrowser

修复拍照偶现闪退问题 #794