remove ReDoS regexp in %o formatter (#504)

Author: zhuangya

src/node.js

@@ -83,7 +83,9 @@ function useColors() {
 exports.formatters.o = function(v) {
  this.inspectOpts.colors = this.useColors;
  return util.inspect(v, this.inspectOpts)
- .replace(/\s*\n\s*/g, ' ');
+ .split('\n').map(function(str) {
+ return str.trim()
+ }).join(' ');
 };
 
 /**