User git config file can interfere with gin-cli operations

If a user has a global configuration or a gin specific configuration somehow, it may interfere with the client's git calls. This _can_ lead to unpredictable behaviour. On the other hand, there may be cases where the user is explicitly configuring the gin-cli behaviour for some reason.

I don't know if we should ignore user configs or respect them.

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The issue presented when using the client with a git configuration that specifies a key for logging into gin.g-node.org. When the client was asked to clone a repository, SSH tried to unlock the desktop keyring in order to use the configured key, even though it wouldn't work against the GIN SSH service (the key is used to SSH into the machine's SSH service). Cancelling the unlock continued normally, since the SSH command then used the key provided by the gin client.