Fix percentage checkbox naming. Fix #4584

public/app/plugins/panel/graph/tab_display.html

@@ -69,7 +69,7 @@
 		</gf-form-switch>
 		<gf-form-switch class="gf-form" ng-show="ctrl.panel.stack"
 			label="Percent" label-class="width-7"
-			checked="ctrl.panel.percent" on-change="ctrl.render()">
+			checked="ctrl.panel.percentage" on-change="ctrl.render()">
 		</gf-form-switch>
 		<div class="gf-form" ng-show="ctrl.panel.stack">
 			<label class="gf-form-label width-7">Tooltip value</label>