integration/client/watch: remove duplicate setup
integration/client/watch: remove duplicate setup

This test was being skipped as it has a duplicate call to
integration2.BeginTest. This duplicate call registered a second handler
for leak detection which failed and skipped the test as the wrapper
(runWatchTest) has already started a cluster.

ajityagaty/etcd,etcd-io/etcd,rnaveiras/etcd,mkumatag/etcd,ajityagaty/etcd,rnaveiras/etcd,mqliang/etcd,mkumatag/etcd,mkumatag/etcd,ajityagaty/etcd,etcd-io/etcd,rnaveiras/etcd,mqliang/etcd,etcd-io/etcd,mqliang/etcd