caddy-git unable to clone repos with non-standard port URL

caddy-git plugin is no longer able to clone repos with non-standard port URL. This was working a few weeks back and could have been introduced by [this change](https://github.com/abiosoft/caddy-git/commit/184099b0f280521813ddb21ad97880c15ebda0a3#diff-4798cfc286af451d8b9373fda343b711)

```
git {
repo ssh://git@stash.abc.net:7999/project/repo.git
key ~/.ssh/id_rsa
}
```
Multiple issues:
* By default, the plugin tries to connect at port 22.

#### error
```
Activating privacy features... done.
Cloning into '/var/www'...
ssh: connect to host stash.abc.net port 22: Connection refused
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
2017/09/07 15:19:58 exit status 128
```

* If the port is specified in `~/.ssh/cong` then it is able to connect to the server but still cannot clone the repo

#### ssh config

```
Host stash.abc.net
StrictHostKeyChecking no
port 7999
```

#### error

```
Activating privacy features... done.
Cloning into '/var/www'...
Repository not found
The requested repository does not exist, or you do not have permission to access it.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
```

I tried the workaround suggested [here](https://github.com/abiosoft/caddy-git/issues/69) but it did not work for me.

Note: I am able to clone the same URL manually.