Inquiry on using jetcd in the vertx server

**Versions**
- etcd: not matter
- jetcd: 0.7.6
- java: JDK8

**Describe the bug**
When using jetcd in a vertx server, every time getKVClient(), there will be warn log '_You're already on a Vert.x context, are you sure you want to create a new Vertx instance?_'
we just want to know，is it normal and does it matter?

**To Reproduce**
execute the following code on a vertx server:
`Client.builder().endPoints({etcd_endpoints}).build().getKVClient()`