FD: fix fd_hbs handling of multiple monitors
FD: fix fd_hbs handling of multiple monitors

we used reference counting to delete a monitor only once but created them every time

scalaris-team/scalaris,jvf/scalaris,caijieming-baidu/scalaris,caijieming-baidu/scalaris,jvf/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris,jvf/scalaris,jvf/scalaris,jvf/scalaris,jvf/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,jvf/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris