Update proxy.js

ups != was right in one of those cases.... 
ummm using typeof may be better? 
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof

examples/proxy/proxy.js

@@ -180,6 +180,6 @@ function shouldDump(name, direction) {
   return matches(printNameWhitelist[name]);
 
   function matches(result) {
-    return result !== null && result.indexOf(direction) !== -1;
+    return result != null && result.indexOf(direction) !== -1;
   }
 }