[BUG] wrong default usage string

[XSven]

According to the documentation "USAGE: %c %o" is the default usage_string. For my program I have configured 2 additional short options -d and -V but they are not shown when I am asking for short (-h) or long help (--help)

USAGE: my_program [-h] [long options ...]

If I am changing the import to this

use MooX::Options usage_string => 'USAGE: %c %o';

I get the expected result

USAGE: my_program [-dhV] [long options ...]