Fix warning

Author: technicalguru

src/WebApp/BootstrapTheme/InlineForm/DateRangeInputRenderer.php

@@ -8,6 +8,8 @@
 
 class DateRangeInputRenderer extends InputRenderer {
 
+	public $period;
+
 	public function __construct($theme, $component) {
 		parent::__construct($theme, $component);
 		$this->theme->addFeature(\WebApp\BootstrapTheme\BootstrapTheme::DATERANGEPICKER);