message: use url according to github documentation
diff: @@ -46,8 +46,8 @@ namespace {
  const QString kDownloadPlatform = "Github";
  const QString kTemplateFmt = "%1-XXXXXX.%2";
  -const QString kLinkFmt = "https://github.com/Murmele/gittyup/releases/download/"
  - "latest/Gittyup%1%2.%3";
  +const QString kLinkFmt = "https://github.com/Murmele/gittyup/releases/latest/"
  + "download/Gittyup%1%2.%3";
  const QString kChangelogUrl =
  "https://raw.githubusercontent.com/Murmele/Gittyup/gh-pages/changelog.md";
  