Mount data custom app data location specifically into sftp addon

Fixes #722

src/apptask.js

@@ -45,6 +45,7 @@ var addons = require('./addons.js'),
     rimraf = require('rimraf'),
     safe = require('safetydance'),
     settings = require('./settings.js'),
+    sftp = require('./sftp.js'),
     shell = require('./shell.js'),
     superagent = require('superagent'),
     sysinfo = require('./sysinfo.js'),
@@ -740,7 +741,12 @@ function migrateDataDir(app, args, progressCallback, callback) {
             debugApp(app, 'error migrating data dir : %s', error);
             return updateApp(app, { installationState: apps.ISTATE_ERROR, error: makeTaskError(error, app) }, callback.bind(null, error));
         }
-        callback(null);
+
+        // We do this after the app has the new data commited to the database
+        sftp.rebuild(function (error) {
+            if (error) console.error('Failed to rebuild sftp addon:', error);
+            callback();
+        });
     });
 }