Change accept urls to match backends

[dpwspoon]

This is just a suggestion. But currently the accept urls on the gateway are generally

ws://kaazing.example.com/ with out a extended path. To be consistent with the shipping gateway-config in kaazing we should add what they are going to on the path. For example ws://kaazing.example.com/redis

[robinzimmermann]

We should provide well-formed URLs. That means including a path, even if it's only /.