Name unused whole match var. in same way as other regex

lib/jsonpath.js

@@ -81,7 +81,7 @@ JSONPath.prototype._normalize = function (expr) {
     var subx = [];
     var normalized = expr.replace(/[\['](\??\(.*?\))[\]']/g, function ($0, $1) {return '[#' + (subx.push($1) - 1) + ']';})
                     .replace(/'?\.'?|\['?/g, ';')
-                    .replace(/(?:;)?(\^+)(?:;)?/g, function (_, ups) {return ';' + ups.split('').join(';') + ';';})
+                    .replace(/(?:;)?(\^+)(?:;)?/g, function ($0, ups) {return ';' + ups.split('').join(';') + ';';})
                     .replace(/;;;|;;/g, ';..;')
                     .replace(/;$|'?\]|'$/g, '');
     var exprList = normalized.split(';').map(function (expr) {