openssl: build with no-async so it doesn't use API not allowed by apple app store
Submitted by Tim-Philipp Müller
Link to original bug (#796367)
Description
Non-public API usage:
The app references non-public symbols in Frameworks/Foobar.framework/Foobar:
_getcontext, _makecontext, _setcontext
https://lists.freedesktop.org/archives/gstreamer-devel/2018-May/067937.html