fix: use preun instead of postun

netoik-cloud.spec

@@ -74,7 +74,7 @@ systemctl daemon-reload
 systemctl reenable nginx.service php-fpm.service
 systemctl restart nginx.service php-fpm.service
 
-%postun
+%preun
 # Display commands and exit on error
 set -xe
 
@@ -89,6 +89,7 @@ if [ $1 == 0 ]; then
   if runuser --user=postgres -- psql --quiet --tuples-only --command='\du' | grep --quiet nextcloud; then
     runuser --user=postgres -- dropuser nextcloud
   fi
+  rm --force /etc/nextcloud/config.php
   rm --recursive --force /var/www/nextcloud
 fi