run-postinsts.service: Removed --no-reload to fix reload warning when users...

run-postinsts.service: Removed --no-reload to fix reload warning when users execute systemctl in the first boot.

This warning is because after systemd has been upgraded to 255, reloading units operation is needed even when "enable/disable" units by systemctl.

Signed-off-by: Lei Maohui <leimaohui@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>