Patch: enforce panel HTTPS, fix set -e SIGPIPE abort, README one-liner

- x-ui-patch.sh: detect when the panel has no TLS cert (empty webCertFile)
  and enable HTTPS the way the main installer does — symlink the Let's
  Encrypt cert into /root/cert/$domain and register it via `x-ui cert`.
  Without this the panel serves plain HTTP and every proxy_pass
  https://127.0.0.1:panel_port (including the diag SSO bridge) fails.
- x-ui-patch.sh: guard the `tr </dev/urandom | head -c N` random generators
  with `|| true`. head closes the pipe, tr dies with SIGPIPE (141), and
  under `pipefail`+`errexit` that intermittently aborts the whole script.
- README: replace the two-step patch download/run block with a single
  curl|bash one-liner (also drops a stale wget filename mismatch).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -42,16 +42,10 @@ bash x-ui-latest.sh -install y -subdomain panel.example.com -reality_domain r.ex
 ---
 ## Патч
 
-**Шаг 1 — скачать скрипт**
+Применить текущие фиксы к существующей установке (без изменений БД):
 
 ```bash
-wget -qO x-ui-latest.sh https://raw.githubusercontent.com/mozaroc/3x-ui-pro/main/x-ui-patch.sh
-```
-
-**Шаг 2 — запустить**
-
-```bash
-bash x-ui-patch.sh
+bash <(curl -fsSL https://raw.githubusercontent.com/mozaroc/3x-ui-pro/main/x-ui-patch.sh)
 ```
 
 ---