Slider spinner.gif mixed content

When served over https my site gets:

Mixed Content: The page at ‘https://rusavto123.ru/’ was loaded over HTTPS, but requested an insecure image ‘https://malsup.github.com/images/spinner.gif’. This content should also be served over HTTPS.

Can’t find this ‘https://malsup.github.com/images/spinner.gif’. But the spinner appears only on slider

Could you please help with the issue

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