pgsql: change wire protocol data type for history file content

change wire protocol data type for history file content

This was marked as BYTEA, but is more like TEXT, which is how we already
pass the history timeline file name.  Internally, we don't do any
encoding or bytea escape handling, but TEXT seems closest.  This should
cause no behavioral change.

Reported-by: Brar Piening

Discussion: https://postgr.es/m/6a1b9cd9-17e3-df67-be55-86102af6bdf5@gmx.de

Backpatch-through: master

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/66a8f090485e3e897a4804121fdbe856cba72d70

Modified Files
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doc/src/sgml/protocol.sgml          | 6 ++++--
src/backend/replication/walsender.c | 2 +-
2 files changed, 5 insertions(+), 3 deletions(-)