Restart web server

src/freedombone-utils-android

     # The FreedomBox app assumes a self-signed cert
     if [ ! -f "/etc/ssl/certs/${local_hostname}.crt" ]; then
         install_web_local_user_interface
+        systemctl restart nginx
     fi
 
     if [ ! -d "/var/www/${local_hostname}/htdocs/plinth/api" ]; then