remove SIGINT handler for single runs; see #3570
remove SIGINT handler for single runs; see #3570

mochajs/mocha,mochajs/mocha,igwejk/mocha,outsideris/mocha,adamgruber/mocha,adamgruber/mocha,adamgruber/mocha,outsideris/mocha,igwejk/mocha,mochajs/mocha