debugger: use strict equality comparison

There is no type-conversion to be done. Therefore, use the === operator.

PR-URL: #2558
Reviewed-By: Rich Trott <[email protected]>

Author: JungMinu

lib/_debugger.js

@@ -173,7 +173,7 @@ Client.prototype._addHandle = function(desc) {
 
   this.handles[desc.handle] = desc;
 
-  if (desc.type == 'script') {
+  if (desc.type === 'script') {
     this._addScript(desc);
   }
 };