pgsql: Allow some recovery parameters to be changed with reload

Allow some recovery parameters to be changed with reload

Change

archive_cleanup_command
promote_trigger_file
recovery_end_command
recovery_min_apply_delay

from PGC_POSTMASTER to PGC_SIGHUP.  This did not require any further
changes.

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/ca28011a-cfaa-565c-d622-c1907c33ecf7%402ndquadrant.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/13b89f96d07ad3da67b57f66c134c3609bd3e98f

Modified Files
--------------
doc/src/sgml/config.sgml                      | 21 +++++++++++++++++----
src/backend/utils/misc/guc.c                  |  8 ++++----
src/backend/utils/misc/postgresql.conf.sample |  4 ----
3 files changed, 21 insertions(+), 12 deletions(-)