It seems that you cannot have both libssl-1.1 and libssl-1.0 installed on Rasbian strech (see also SSL linking problem in Raspbian GNU/Linux 9 (stretch) · Issue #265 · Azure/azure-iot-sdk-c · GitHub). maybe this was cuasing an issue for you?
I wonder what would happen if the library is compiled with libssl-1.1.0. Would it still work on a Rasbian Jessie with libssl-1.0?