PublicDashboards: Fix GET public dashboard that doesn't match

PublicDashboards: Fix GET public dashboard that doesn't match

pkg/services/publicdashboards/database/database.go

@@ -163,10 +163,13 @@ func (d *PublicDashboardStoreImpl) FindByDashboardUid(ctx context.Context, orgId
 	pdRes := &PublicDashboard{OrgId: orgId, DashboardUid: dashboardUid}
 	err := d.sqlStore.WithTransactionalDbSession(ctx, func(sess *db.Session) error {
 		// publicDashboard
-		_, err := sess.Get(pdRes)
+		exists, err := sess.Get(pdRes)
 		if err != nil {
 			return err
 		}
+		if !exists {
+			return ErrPublicDashboardNotFound
+		}
 
 		return nil
 	})