LFSR button was permanently disabled until RUNTIME or STUCK_OPEN after...

LFSR button was permanently disabled until RUNTIME or STUCK_OPEN after PASS_THRU selected in model_menu
Is now also enabled for other fault models

Tk/FIJISettingsViewer.pm

@@ -386,6 +386,7 @@ sub _update_fields {
            $model eq 'DELAY' ||
            $model eq 'SEU') {
     $self->_set_fields(0, $so_entry);
+    $self->_set_fields(1, $lfsr_button);
     $self->_set_fields_by_button($lfsr_button, $mask_entry); # do not hard-enable $mask_entry
   } else {
     $logger->error("Unknown model selected: $model");