Prevent tooltip open if cursor leaves element (#13695)

Change-Id: I81b1955aba56207cb63d78113f698c0ae65a599b

client/src/com/vaadin/client/VTooltip.java

@@ -404,9 +404,7 @@ public class VTooltip extends VWindowOverlay {
 
             TooltipInfo info = getTooltipFor(element);
             if (info == null) {
-                if (isActuallyVisible()) {
-                    handleHideEvent();
-                }
+                handleHideEvent();
             } else {
                 setTooltipText(info);
                 updatePosition(event, isFocused);