join_leave_SUITE: disable monitor_perf for tests verifying data size
join_leave_SUITE: disable monitor_perf for tests verifying data size

with the monitor perf, it could happen that an intermediate snapshot is taken and the expected number of items is not correct (the monitor_perf performs a read-read-commit tx and thus creates temporary items)
jvf/scalaris,scalaris-team/scalaris,jvf/scalaris,jvf/scalaris,jvf/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,jvf/scalaris,caijieming-baidu/scalaris,jvf/scalaris,jvf/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris,caijieming-baidu/scalaris,caijieming-baidu/scalaris,scalaris-team/scalaris