Autoblog- Secure RSS Wordpress Issue

A Wordpress site that we are developing has the following error when trying to add an RSS feed from a secure URL: "SSL certificate problem, verify that the CA cert is OK. Details: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed"

After researching various plugins, I discovered that Autoblog has the following option when adding feeds (hence the reason for us purchasing this plugin):
"Force SSL verification"

The same error occurs when either "Yes" or "No" is selected.

The secure RSS feed is:
https://www.osha.gov/as/opa/quicktakes/quicktakes.xml

We hope to hear from your support team as soon as possible, as this is time-sensitive.