If you are on dedicated server and encounter "Protocol https not supported or disabled in libcurl", here is what you need to do.
I had such issue and cost me hours to figure it out because my hosting provider could not be of help. But finally, I research deeply and got it resolved by recompiling my Apache with "curlURL" and disable "curl" in EasyApache.
I also discovered on CPANEL forum that the error is due to the bug in EasyApache 3.9.1.
It is stated on CPANEL forum that "If you / your web host recompiled Apache since EasyApache 3.9.1 came out, it may have compiled but may have set the system to only compile in curl and not curlSSL. You don't want to select both in EasyApache - it's one or the other. The curlssl option will allow for non-ssl functionality as well."
Thanks for sharing your experience. It will serve as guide to others who may encounter such issue.