[Bug-ddrescue] unrecognized option `--binary-prefixes'

[fctk86]

hello,

i'm unable to use the `--binary-prefixes' option in ddrescue-1.7 instead 
of the `-B' option. i get the following error message:

$ ./ddrescue --binary-prefixes
ddrescue: unrecognized option `--binary-prefixes'
Try `./ddrescue --help' for more information.

this should be easy to fix... :)