cloud_discovery: rtrim() the extracted subject

this removes trailing \n\n characters

Fixes: WIFI-14694
Signed-off-by: John Crispin <john@phrozen.org>

feeds/tip/cloud_discovery/files/usr/bin/cloud_discovery

@@ -159,6 +159,7 @@ function generate_csr() {
 		let pipe = fs.popen('openssl x509 -in /etc/ucentral/cert.pem -noout -subject');
 		let subject = pipe.read("all");
 		pipe.close();
+		subject = rtrim(subject);
 		subject = replace(subject, 'subject=', '/');
 		subject = replace(subject, ' = ', '=');
 		subject = replace(subject, ', ', '/');