Fix typo in login example in README

Author: pgier

README.md

@@ -87,7 +87,7 @@ OkHttpClient httpClient = new OkHttpClient();
 * Afer this, the user must signin on google and get the token that will be show to him.
 * This token will need to be put as argument to login.
 */
-GoogleUserCredentialProvider provider = new GoogleUserCredentialProvider(http);
+GoogleUserCredentialProvider provider = new GoogleUserCredentialProvider(httpClient);
 
 // in this url, you will get a code for the google account that is logged
 System.out.println("Please go to " + GoogleUserCredentialProvider.LOGIN_URL);