--debug doesn't invoke --inspect correctly

[boneskull]

at least, in theory, because of this typo:

mocha/bin/mocha

Lines 42 to 46 in 1e30501

	// allow --debug to invoke --inspect on Node.js v8 or newer nodeOpts.inspect = childOpts.debug;
	if (childOpts.debug) {
	childOpts.timeout = false;
	delete childOpts.debug;
	debug('--debug -> --inspect');