test/t_client: use EventLoop::{Break,Dispatch}() in test_data_blocking()
test/t_client: use EventLoop::{Break,Dispatch}() in test_data_blocking()

CM4all/beng-proxy,CM4all/beng-proxy,CM4all/beng-proxy,CM4all/beng-proxy,CM4all/beng-proxy,CM4all/beng-proxy