Remove potential ending line break when using edebug() with LoggerInterface

src/SMTP.php

@@ -281,7 +281,7 @@ class SMTP
         //Is this a PSR-3 logger?
         if ($this->Debugoutput instanceof \Psr\Log\LoggerInterface) {
             //Remove ending line breaks potentialy added by calls to SMTP::client_send()
-            $str = preg_replace('/[\r\n]+$/', '', $str);
+            $str = rtrim($str, "\n\r");
             $this->Debugoutput->debug($str);
 
             return;