pgsql: pg_basebackup: Remove short option -k

pg_basebackup: Remove short option -k

-k meant --no-verify-checksums, which is the opposite of what initdb
uses -k for. After discussion, a short option does not seem necessary,
so just keep the long option.

Discussion: /messages/by-id/d510f8aa-19e1-d06e-7630-ad27f7441d68@2ndquadrant.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/3ce7f72529f5829f73e18240740bafc939b650b5

Modified Files
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doc/src/sgml/ref/pg_basebackup.sgml | 35 ++++++++++++++--------------
src/bin/pg_basebackup/pg_basebackup.c | 10 ++++----
src/bin/pg_basebackup/t/010_pg_basebackup.pl | 2 +-
3 files changed, 23 insertions(+), 24 deletions(-)