Remove Gravatar or replace its URL with https:// (SSL issue)

[mettacell]

Hello all. This is my first post, I apologise in advance for any inappropriate move. 

I have SSL on my Sentora server. It all loads fine with https://... url pattern. But it gives me a message (or ruins the green SSL symbol to yellow) as the Gravatar image on the top right loads as an insecure/non-ssl image. 

So I am trying to get a fix either by completely removing the Gravatar image or if any kind friend has a suggestion to share that could properly deliver the Gravatar image with https://... - will be just great!

I should mention that it's a Zentora theme I am using.

I have looked into the core files but could not locate from where the Gravatar gets a call in the code.

Any help will be greatly appreciated. Thanks in advance.