Editor freezes while sync-settings checking the backup

**Describe the bug**
Editor freezes while sync-settings checking the backup.

**To Reproduce**
Steps to reproduce the behavior:
1. Open the editor and the editor will freeze a few seconds.

**Expected behavior**
Able to edit or do something other things while sync-settings checking the backup.

**Screenshots**

- When I click somewhere, the yellow circle will be exposed.

**Versions**
OS: Win 10 Pro x64 (18363.815)
Atom : 1.46.0
Electron: 4.2.7
Chrome : 69.0.3497.128
Node : 10.11.0

apm 2.4.3
npm 6.2.0
node 10.2.1 x64
atom 1.46.0
python 2.7.17
git 2.26.2.windows.1
visual studio 2015

Start by reproducing the freeze while sync-settings checks its backup, using the reported Windows, editor, Electron, and Node versions, then trace the backup-checking path in the JavaScript package. Done means the editor remains responsive and usable while the backup check runs.

Written by the indexing model from the issue text.