Avoid eMail misses new-lines of a message when non-ascii included.

pandora_server/lib/PandoraFMS/Core.pm

@@ -1080,7 +1080,7 @@ sub pandora_execute_action ($$$$$$$$$;$) {
 		# non-ascii chars should be encoded in UTF-8.
 		if ($field3 =~ /[^[:ascii:]]/o) {
 			$field3 = encode("UTF-8", $field3);
-			$content_type = 'text/html; charset="UTF-8"';
+			$content_type = 'text/plain; charset="UTF-8"';
 		}
 		
 		# Build the mail with attached content