Log Message:
archivers/star: Update to 1.6.1nb9

Changelog from AN-2020-07-01:
- star: Backslashes are now honored when looking for the substitution
  separators in options like -s /from/to/ or -pax-s /from/to/

  Previously, -s '/xxx\/yy//' was interpreted in a way that made
  the **to string** "yy" and the **from string** "xxx\" \ 
instead of
  making the from string "xxx\/yy" and the to string empty.