Remove previous handler when listener unsubscribed

Author: alexgb

lib/platforms/react-native.js

@@ -19,6 +19,7 @@ export const dance = (authUrl) => {
 
       const onLinkChange = ({ url }) => {
         Linking.removeEventListener('url', onLinkChange);
+        previousOnLinkChange = undefined;
         handleUrl(url);
       };