[Rd] webpage link (to MacOSX check summaries) is broken (PR#7405)

[smyth at wehi.edu.au]

The link to "MacOS X check summary" on the page

   http://cran.r-project.org/src/contrib/PACKAGES.html

is broken.

Gordon
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Dr Gordon K Smyth, Senior Research Scientist, Bioinformatics,
Walter and Eliza Hall Institute of Medical Research,
1G Royal Parade, Parkville, Vic 3050, Australia
Tel: (03) 9345 2326, Fax (03) 9347 0852,
Email: smyth at wehi.edu.au, www: http://www.statsci.org