DE4173: f9_phone Plugin Crash - firefox hangs up on mac while auto-testing

the FireBreath attempts to write into stdout every log message sending to a browser console, and since web driver makes browsers write stdout to a pipe sometime such a browser hangs on writing attempt because the pipe is full
Merge pull request #3 from ariesnah/feature/removing-printf

DE4173: f9_phone Plugin Crash - firefox hangs up on mac while auto-testing