patchverify-tag: Parse GPG configuration options.

> Modify verify-tag to load relevant GPG variables from the git
> configuratio file.  This allows git tag -v to use an alternative
> GPG binary in the same way that git tag -s does.
>
> Signed-off-by: Alex Zepeda <alex@inferiorhumanorgans.com>
> ---

>  builtin/verify-tag.c |   10 +++++++++-
>  1 files changed, 9 insertions(+), 1 deletions(-)
>
> diff --git a/builtin/verify-tag.c b/builtin/verify-tag.c
> index 28c2174..986789f 100644
> --- a/builtin/verify-tag.c
> +++ b/builtin/verify-tag.c
> @@ -58,6 +58,14 @@ static int verify_tag(const char *name, int verbose)
>  	return ret;
>  }
>  
> +static int git_verify_tag_config(const char *var, const char *value, void *cb)
> +{
> +	int status = git_gpg_config(var, value, cb);
> +	if (status)
> +		return status;
> +	return git_default_config(var, value, cb);
> +}
> +
>  int cmd_verify_tag(int argc, const char **argv, const char *prefix)
>  {
>  	int i = 1, verbose = 0, had_error = 0;
> @@ -66,7 +74,7 @@ int cmd_verify_tag(int argc, const char **argv, const char *prefix)
>  		OPT_END()
>  	};
>  
> -	git_config(git_default_config, NULL);
> +	git_config(git_verify_tag_config, NULL);
>  
>  	argc = parse_options(argc, argv, prefix, verify_tag_options,
>  			     verify_tag_usage, PARSE_OPT_KEEP_ARGV0);