Missing similarity (-S) option in usage output

[danpal96]

Nonpareil v3.4.1

The -L option in the usage output talks about a similarity option (-S) but it is not described in the usage output.

 -L <num> : Minimum overlapping percentage of the aligned region
             on the largest sequence. The similarity (see -S) is 
             evaluated for the aligned region only.
             By default: 50