Remove duplicate locking

Fixes duplicated code after merge

client/client.go

@@ -225,8 +225,6 @@ func (client *Client) do(funcname string, data []byte,
 	if client.conn == nil {
 		return "", ErrLostConn
 	}
-	client.Lock()
-	defer client.Unlock()
 	var result = make(chan handleOrError, 1)
 	client.Lock()
 	defer client.Unlock()