[osx][qt] Fix openssl issue
[osx][qt] Fix openssl issue

Pin homebrew version so that a previous version of the qt bottle is
installed. Current versions cause an issue with the openssl libraries.

The commit on homebrew that breaks our build is:
https://github.com/Homebrew/homebrew/commit/a7ce480

DataDog/omnibus-software,StackVista/omnibus-software,StackVista/omnibus-software