revert the usage of const since it cant be redefined causing potential issues when cwd is used but use var to fix the undefined issue.

Author: ctalkington

lib/core.js

@@ -719,7 +719,7 @@ Archiver.prototype.glob = function(pattern, options, data) {
   }
 
   function onGlobMatch(match){
-    const entryData = _.extend({}, data);
+    var entryData = _.extend({}, data);
 
     if (options.cwd) {
       entryData.name = match;