"FATAL: the database system is starting up" and hot_standby = on

Hi,

There is a standalone server with Postgresql 9.6.3 on Windows 2016 Server.

I had been faced with "FATAL: the database system is starting up" after
disk failure. This mailing list helped me to solve issue by setting
"hot_standby = on" in postgresql.conf.
But I can't fully understand why it had worked.

Comments in conf says, that the setting has to be ignored in my case:
===
# - Standby Servers -
# These settings are ignored on a master server.
hot_standby = on # "on" allows queries during recovery
# (change requires restart)
===

But it is standalone installation, not slave, there is no replication.
Though there is no recovery.conf and any sign of pending recovery nor in
log, nor in postgres.exe output with debug level 5.

Why setting "hot_standby = on" had helped me with "FATAL: the database
system is starting up" error on standalone server? Any ideas?