apiClient.fetchUser() error return html

[zhaotianming1987]

because：
RequestUtil.java

String prefix = BASE_URI + "/api/oauth2/api/";
URL url = new URL(prefix.concat(pathSuffix));

the url is   https://www.patreon.com/api/oauth2/api//current_user?include=pledges   

An extra one/

Right URL is  https://www.patreon.com/api/oauth2/api/current_user?include=pledges