Use isReachableViaWiFi instead of isReachableViaWiFi() on README.md

README.md

@@ -141,7 +141,7 @@ reachability.whenReachable = { reachability in
     // this is called on a background thread, but UI updates must
     // be on the main thread, like this:
     DispatchQueue.main.async {
-        if reachability.isReachableViaWiFi() {
+        if reachability.isReachableViaWiFi {
             print("Reachable via WiFi")
         } else {
             print("Reachable via Cellular")