Bump agent to 7859eb4
Bump agent to 7859eb4

- Fix Elixir linking issue with extension.

appsignal/appsignal-ruby,appsignal/appsignal-ruby,appsignal/appsignal-ruby,appsignal/appsignal-ruby,matrinox/appsignal-ruby,appsignal/appsignal,appsignal/appsignal,matrinox/appsignal-ruby,matrinox/appsignal-ruby