Fix typo in link for pisugar-programmer rpm package

[withoutgettingwet]

Replaced an underscore with a dash before the ${version} variable in the line that links to the pisugar-programmer rpm package, previously led to 404 regardless of version. Previously referenced in PiSugar/PiSugar#130

[withoutgettingwet]

I couldn't find PiSugarUpdate.sh anywhere in this repository, so note that this does not fix the problem with PiSugarUpdate.sh mentioned in the above issue:

In PiSugarUpdate.sh, referenced on the same wiki page as above, lines 19, 20, and 47 are hardcoded to use programmer 1.6.4 (now out of date) and only in a deb package for armhf architecture. There is also a very minor typo (will not effect function) in line 25 where it says "stoping" instead of "stopping".