Change some URLs from author dirs to dist dirs.
The example in the porter's handbook didn't have the trailing slash;
mea culpa for not having caught that when it went in.
in RFC 1950. The interface provided by this module is specified in Digest,
but no functional interface is provided.
WWW: http://search.cpan.org/dist/Digest-Adler32
PR: ports/90545
Submitted by: Gabor Kovesdan
