proxy/grpcproxy: Add critical section to protect wps.watchers and wps.nextWatcherID
proxy/grpcproxy: Add critical section to protect wps.watchers and wps.nextWatcherID

mqliang/etcd,cockroachdb/etcd,mkumatag/etcd,cockroachdb/etcd,ajityagaty/etcd,rnaveiras/etcd,etcd-io/etcd,dannysauer/etcd,li-ang/etcd,rnaveiras/etcd,dannysauer/etcd,mkumatag/etcd,rnaveiras/etcd,mqliang/etcd,li-ang/etcd,coreos/etcd,mqliang/etcd,ajityagaty/etcd,gyuho/etcd,etcd-io/etcd,ajityagaty/etcd,gyuho/etcd,coreos/etcd,etcd-io/etcd,mkumatag/etcd