fix: sshnpd updater patches

[XavierChanth]

- What I did

• moved post_install function to run before restarting sshnpd
• service restarter now restarts like so:
  killall -qu "$SSHNP_USER" -r "$BINARY_NAME$"
  which ensures that the restarter loop keeps running in the background

- How I did it

- How to verify it

- Description for the changelog
fix: sshnpd updater patches

[cconstab]

I get an odd error on pi

spi0(183): Operation not permitted

running with bash -x

Installation complete!
+ '[' update = update ']'
+ restart_service
+ killall -qu pi -r 'sshnpd$'
spi0(183): Operation not permitted
pi@xmt-pi:~ $

should read

killall -q -u pi -r 'sshnpd$'

typo on line 262

[cconstab]

tested on Pi works fine