Merge pull request #4765 from viitols/develop

Fix CI_Email not sending User-Agent header
diff --git a/system/libraries/Email.php b/system/libraries/Email.php
index e250154..a5a7079 100644
--- a/system/libraries/Email.php
+++ b/system/libraries/Email.php
@@ -1215,6 +1215,7 @@
 	 */
 	protected function _build_headers()
 	{
+		$this->set_header('User-Agent', $this->useragent);
 		$this->set_header('X-Sender', $this->clean_email($this->_headers['From']));
 		$this->set_header('X-Mailer', $this->useragent);
 		$this->set_header('X-Priority', $this->_priorities[$this->priority]);