Hi Bogdan,
I'm able to replicate the issue by using the link you've given above
What you said earlier give us the hint a bit on the issue
Can you download the temporary fix file(attached) and replace in the:
.../administrator/components/com_easysocial/includes/connector/adapters/curl.php
and see how it goes.
You're suggested to backup the file that you want to replace beforehand for precaution