notify/smtp.sh: add --crlf so curl sends CRLF line endings

Postfix with smtpd_forbid_bare_newline (default hardening since 3.9,
after SMTP smuggling) rejects the message with
"521 5.5.2 Error: bare <LF> received". RFC 5321 requires CRLF.
The python sender is unaffected (smtplib already emits CRLF).

fix https://github.com/acmesh-official/acme.sh/issues/7104

notify/smtp.sh

@@ -200,6 +200,7 @@ _smtp_send_curl() {
 
   set -- "$@" \
     --upload-file - \
+    --crlf \
     --mail-from "$SMTP_FROM" \
     --max-time "$SMTP_TIMEOUT"