pgsql: Unify some error messages to ease work of translators

Unify some error messages to ease work of translators

This commit updates a couple of error messages around control file data,
GUCs and server settings, unifying to the same message where possible.
This reduces the translation burden a bit.

Author: Peter Smith
Discussion: /messages/by-id/CAHut+Pv-kSN8SkxSdoHano_wPubqcg5789ejhCDZAcLFceBR-w@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/a68159ff2b32f290b1136e2940470d50b8491301

Modified Files
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src/backend/access/transam/xlog.c | 80 +++++++++++++++++++++++++--------------
src/backend/commands/variable.c | 6 ++-
src/backend/storage/file/fd.c | 9 +++--
src/backend/utils/fmgr/dfmgr.c | 20 ++++++----
4 files changed, 73 insertions(+), 42 deletions(-)