[#301] rpc: Make client stream initialization get cancelled by dial timeout

* `c.conn` may be already invalidated but the rpc client can't detect this.
  `NewStream` may hang trying to open a stream with invalidated connection.
  Using timer with `dialTimeout` for `NewStream` fixes this problem.

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>

api/rpc/client/init.go

@@ -61,7 +61,8 @@ func (c *Client) Init(info common.CallMethodInfo, opts ...CallOption) (MessageRe
 	// would propagate to all subsequent read/write operations on the opened stream,
 	// which is not desired for the stream's lifecycle management.
 	dialTimeoutTimer := time.NewTimer(c.dialTimeout)
-	newStreamCh := make(chan interface{})
+	defer dialTimeoutTimer.Stop()
+	newStreamCh := make(chan struct{})
 
 	var stream grpc.ClientStream
 	var err error