Fix wrong order of issues when importing from github

### 1. What does this MR do?

The order of issues imported from GitHub is fixed.

### 2. Are there points in the code the reviewer needs to double check?

Nothing.

### 3. Why was this MR needed?

The default behaviors of GitHub API at listing issues are sort: :created and direction: :desc.

See GitHub API details at https://developer.github.com/v3/issues/#list-issues.

### 4. What are the relevant issue numbers / Feature requests?

Fixes #1791

### 5. Screenshots (if relevant)

Nothing

See merge request !898