Reenable test now that we have a higher timeout for Tunit

netwerk/test/unit/test_plaintext_sniff.js

@@ -166,9 +166,6 @@ function makeHandler(headerIdx, bodyIdx) {
 
 var httpserv;
 function run_test() {
-  // Disabling test for now because tinderbox somehow fails to deal
-  return;
-  
   httpserv = new nsHttpServer();
 
   for (i = 0; i < contentTypeHeaderList.length; ++i) {