rpc error: code = DeadlineExceeded desc = context deadline exceeded

Hi, and thank you for making the `gnxi` utilities available.

The binaries have been built and installed without any errors using golang `go1.17.13`. But,

I am failing to contact a router using `gnmi_capabilities` (or `gnmi_get`). The error message is as follows:
```
~/go/bin/gnmi_capabilities -target_name "prod-lab03a-rd1" -target_addr x.x.x.x:57400 -username xxx -password xxx -alsologtostderr -logtostderr -v 1 -insecure true -notls true
F0426 11:26:02.260135 6501 gnmi_capabilities.go:59] error in getting capabilities: rpc error: code = DeadlineExceeded desc = context deadline exceeded
```
while there is connectivity:
```
> nc -vz x.x.x.x 57400
Connection to x.x.x.x 57400 port [tcp/*] succeeded!
```

Using another grpc client, it succeeds as well:
```
/usr/local/sbin/gnmic --address x.x.x.x:57400 --username xxx --password xxx --insecure capabilities
```

Do you have perhaps any idea what might be going wrong here?