Use HTTPS to fetch external js resources

When putting a generated html on https capable webservers, external
libraries like AngularJS will be blocked by web browser as mixed content
of http/https. For more detail, please refer to:
https://developer.mozilla.org/docs/Security/MixedContent/How_to_fix_website_with_mixed_content

Change-Id: Ied2e74b29d6c2b303cafdf71fb97bdb5460f400a
Merge "Use HTTPS to fetch external js resources"