pgsql: Replace search.cpan.org with metacpan.org

Replace search.cpan.org with metacpan.org

search.cpan.org has been EOL'd, with metacpan.org being the official
replacement to which URLs now redirect.  Update links to match the new
URL. Also update links to CPAN to use https as it will redirect from
http.

Author: Daniel Gustafsson
Discussion: https://postgr.es/m/B74C0219-6BA9-46E1-A524-5B9E8CD3BDB3@yesql.se

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/dad335b89f2e1d543ef8226b7de4b191246a06dd

Modified Files
--------------
contrib/fuzzystrmatch/dmetaphone.c  | 2 +-
doc/src/sgml/acronyms.sgml          | 2 +-
doc/src/sgml/external-projects.sgml | 2 +-
doc/src/sgml/install-windows.sgml   | 2 +-
src/test/perl/PostgresNode.pm       | 2 +-
5 files changed, 5 insertions(+), 5 deletions(-)