fix organization wording in psql's \copyright command

It looks like \copyright didn't get updated in commit 5987553. I plan to
back-patch this down to v13 once the tag for 18beta2 is pushed.

diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index a2e009ab9be..8c62729a0d1 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -748,7 +748,7 @@ void
print_copyright(void)
{
puts("PostgreSQL Database Management System\n"
- "(formerly known as Postgres, then as Postgres95)\n\n"
+ "(also known as Postgres, formerly known as Postgres95)\n\n"
"Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group\n\n"
"Portions Copyright (c) 1994, The Regents of the University of California\n\n"
"Permission to use, copy, modify, and distribute this software and its\n"

--
nathan