Update to use dropbox api version 2

Author: jackycute

lib/auth.js

@@ -95,6 +95,7 @@ if (config.gitlab) {
 //dropbox
 if (config.dropbox) {
     passport.use(new DropboxStrategy({
+        apiVersion: '2',
         clientID: config.dropbox.clientID,
         clientSecret: config.dropbox.clientSecret,
         callbackURL: config.serverurl + '/auth/dropbox/callback'