`sketch -L` doesn't work

[BenLangmead]

The -L parameter for the sketch subcommand does not work as advertised. I get:

sketch: invalid option -- 'L'

Followed by usage message. If I replace -L with the long version of the parameter, --sketch-size-l2, it works fine. I took a brief look at the code and found the getopt struct for this option but didn't immediately see what might be wrong with it.

[dnbaker]

Found the problem - missing "L" in the getopt string. I've prepared its fix with a CLI sanity check (making sure there are no unexpected flags)