get actual error from TT2 object

lib/IdPAccountManager/WebRequest.pm

@@ -393,7 +393,7 @@ sub req_generate_token {
 
     unless ($tt2->process($template, $data, $handle)) {
         push @{ $self->{out}->{errors} }, "mail_notification_error";
-        $self->{logger}->errorf("Mail notification error: %s", $EVAL_ERROR);
+        $self->{logger}->errorf("Mail notification error: %s", $tt2->error());
         return undef;
     }