v1.7.1

Fix

1. SAN certification saved folder path is wrong
2. UI Style broken after changing theme preference and then refresh the page.

Enhance

1. Check nginx config syntax before save
2. Throw error detail and fallback to original file contents if fail to parse nginx configuration
3. Add multi-platform Docker images #60

For more change log about v.1.7.0 please check v1.7.0 Release Note.