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.
ElfHash generates resonably 32 bit integer value from a string in a
reasonably short period of time.
WWW: http://search.cpan.org/dist/Digest-Elf
PR: ports/90561
Submitted by: Gabor Kovesdan