New apps that use UIWebView are no longer accepted.

1.移除Libraries/RNCWebView.xcodeproj/RNCUIWebView.h、RNCUIWebView.m、RNCUIWebViewManager.h、RNCUIWebViewManager.m

2.移除Libraries/React.xcodeproj/React/Views/RCTWebView.h、RCTWebView.m、RCTWebViewManager.h、RCTWebViewManager.m