Update nginxproxymanager-install.sh

tweak

install/nginxproxymanager-install.sh

@@ -39,7 +39,7 @@ $STD apt-get install -y \
   python3-cffi \
   python3-certbot \
   python3-certbot-dns-cloudflare
-  pip3 install certbot_dns_porkbun
+$STD pip3 install certbot_dns_porkbun
 $STD python3 -m venv /opt/certbot/
 msg_ok "Installed Python Dependencies"