"Other docs" folder is deleted after disconnect and reconnect with same user

Steps to reproduce :

1. Install DS.
2. Login to DS with valid Ceredentials.
3. Wait for complete sync.
4. Go to settings -> Account tab.
5. Disconnect the user and reconnect with same user
6. Other docs is not visible in folder but in sync folder other docs is shown. In Local system Other docs folder is in recycle bin.

Cause for this issue :

https://github.com/nuxeo/nuxeo-drive/commit/8d7e78e7b061202d7daa14cd476a4b3dde318ce4#diff-3ac0d3ca326afdda837555bfc7266b34R509

The problem with code (newly introduced in nuxeo-drive 2.5.4) is that it deletes the virtual roots (like 'Other Docs' folder) as it does not exists in server side.
remote_ref for Other Docs will be like sharedSyncRootParentFactory#