Tests occasionally fail since #12000:
```
*** [err]: query buffer resized correctly when not idle in tests/unit/querybuf.tcl
Expected 0 > 32768 (context: type eval line 11 cmd {assert {$orig_test_client_qbuf > 32768}} proc ::test)
*** [err]: query buffer resized correctly with fat argv in tests/unit/querybuf.tcl
query buffer should not be resized when client idle time smaller than 2s
```
The reason may be because we set hz to 100, querybuf shrinks before we count
client_query_buffer. We avoid this problem by setting pause-cron to 1.
e49c2a5292