Change variable name to remove reserved keyword

lib/common/utils.js

@@ -186,8 +186,8 @@ function isWhiteSpace(code) {
 var UNICODE_PUNCT_RE = require('uc.micro/categories/P/regex');
 
 // Currently without astral characters support.
-function isPunctChar(char) {
+function isPunctChar(ch) {
-  return UNICODE_PUNCT_RE.test(char);
+  return UNICODE_PUNCT_RE.test(ch);
 }