fix(iOS): javaScriptEnabled property (#826)

ios/RNCWKWebViewManager.m

@@ -49,6 +49,7 @@ RCT_EXPORT_VIEW_PROPERTY(onLoadingError, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(onLoadingProgress, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(onShouldStartLoadWithRequest, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(injectedJavaScript, NSString)
+RCT_EXPORT_VIEW_PROPERTY(javaScriptEnabled, BOOL)
 RCT_EXPORT_VIEW_PROPERTY(allowsInlineMediaPlayback, BOOL)
 RCT_EXPORT_VIEW_PROPERTY(mediaPlaybackRequiresUserAction, BOOL)
 #if WEBKIT_IOS_10_APIS_AVAILABLE