Merge pull request #1577 from kmlebedev/grpc_waitforeeady

add WaitForReady to grpc DialOption. this will affect all grpc calls. Not quite sure about the possible effects. let's see.

weed/pb/grpc_client_server.go

@@ -62,6 +62,7 @@ func GrpcDial(ctx context.Context, address string, opts ...grpc.DialOption) (*gr
 		grpc.WithDefaultCallOptions(
 			grpc.MaxCallSendMsgSize(Max_Message_Size),
 			grpc.MaxCallRecvMsgSize(Max_Message_Size),
+			grpc.WaitForReady(true),
 		),
 		grpc.WithKeepaliveParams(keepalive.ClientParameters{
 			Time:                30 * time.Second, // client ping server if no activity for this long