Add -f because the file is likely to not exist in many cases ?

scripts/upgrade

@@ -26,8 +26,7 @@ final_path=$(ynh_app_setting_get $app final_path)
 #=================================================
 
 # Removing configuration files with naming that occured in versions < 1.2.0 ("vpnadmin" instead off "$app")
-rm /etc/nginx/conf.d/${domain}.d/vpnadmin.conf 2>/dev/null 
-
+rm -f /etc/nginx/conf.d/${domain}.d/vpnadmin.conf 2>/dev/null 
 rm -f /etc/php/*/fpm/pool.d/vpnadmin.conf 2>/dev/null 
 
 if [ -d /var/www/vpnadmin ]; then