More error output if update() in foxx manager fails.

This is a temporary output to track down the continuous testing
problems.

js/client/modules/org/arangodb/foxx/manager.js

@@ -311,6 +311,7 @@ function updateFishbowl () {
     }, filename);
 
     if (result.code < 200 || result.code > 299) {
+      require("internal").print("BadBadBad, something bad has happened:\n", JSON.stringify(result));
       throwDownloadError("Github download from '" + url + "' failed with error code " + result.code);
     }