Bug#894309: update to version 1.0.1 (released Nov '17 on github)

[Sylwester Arabas]

Package: blitz++

Hello,

Blitz++ development has moved two years ago to github:
https://github.com/blitzpp/blitz

There have since been two releases:
- 1.0.0 on 29 Feb 2016,
- 1.0.1 on 2 Oct 2017

HTH,
Sylwester