Before this change, the function could print an error in some cases, for example;
```bash
docker -H tcp://127.0.0.1:2375 info --format '{{.LoggingDriver}}'
template: :1:2: executing "" at <.LoggingDriver>: reflect: indirection through nil pointer to embedded struct field Info
```
With this patch applied, the error is handled gracefully, and when failing to
connect with the daemon, the error is logged;
```bash
docker -H tcp://127.0.0.1:2375 info --format '{{.LoggingDriver}}'
Cannot connect to the Docker daemon at tcp://127.0.0.1:2375. Is the docker daemon running?
docker -H tcp://127.0.0.1:2375 info --format '{{json .}}'
Cannot connect to the Docker daemon at tcp://127.0.0.1:2375. Is the docker daemon running?
{"ID":"","Containers":0,"..."}}
```
Note that the connection error is also included in the JSON `ServerErrors` field,
so that the information does not get lost, even if STDERR would be redirected;
```bash
docker -H tcp://127.0.0.1:2375 info --format '{{json .ServerErrors}}' 2> /dev/null
["Cannot connect to the Docker daemon at tcp://127.0.0.1:2375. Is the docker daemon running?"]
```
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
e96e17d102