repo-config: fix segfault with no argument.

An earlier addition of --list feature was carelessly done and
caused an invalid access to argv[1] when it was not given.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

repo-config.c

@@ -102,15 +102,14 @@ int main(int argc, const char **argv)
 			type = T_INT;
 		else if (!strcmp(argv[1], "--bool"))
 			type = T_BOOL;
+		else if (!strcmp(argv[1], "--list") || !strcmp(argv[1], "-l"))
+			return git_config(show_all_config);
 		else
 			break;
 		argc--;
 		argv++;
 	}
 
-	if (!strcmp(argv[1], "--list") || !strcmp(argv[1], "-l"))
-		return git_config(show_all_config);
-
 	switch (argc) {
 	case 2:
 		return get_value(argv[1], NULL);