devel/R-cran-sessioninfo: Update to 1.2.3
Add www/R-cran-gh to TEST_DEPENDS.
Update WWW to canonical form as cran page suggests.
The `make test' fails, reported on project page, add TESTING_UNSAFE.
Changelog:
https://cran.r-project.org/web/packages/sessioninfo/news/news.html
Reported by: portscout