Update RNCWebView.m

Block methods relating to pull to refresh when the target is macOS as macOS does not have the UIRefreshControl

apple/RNCWebView.m

     [_webView reload];
   }
 }
-
+#if !TARGET_OS_OSX
 - (void)addPullToRefreshControl
 {
     UIRefreshControl *refreshControl = [[UIRefreshControl alloc] init];
     [refreshControl endRefreshing];
 }
 
-#if !TARGET_OS_OSX
+
 - (void)setPullToRefreshEnabled:(BOOL)pullToRefreshEnabled
 {
     _pullToRefreshEnabled = pullToRefreshEnabled;