Simplified another #if/def

ios/RNCWebView.m

   [_webView stopLoading];
 }
 
+#if !TARGET_OS_OSX
 - (void)setBounces:(BOOL)bounces
 {
   _bounces = bounces;
-#if !TARGET_OS_OSX
   _webView.scrollView.bounces = bounces;
-#endif // !TARGET_OS_OSX
 }
+#endif // !TARGET_OS_OSX
 
 - (NSURLRequest *)requestForSource:(id)json {
   NSURLRequest *request = [RCTConvert NSURLRequest:self.source];