haproxy1.9, SPOA: too many open files

[Kevin Zhu]

Use haproxy-1.9 and 2.0, SPOA will occure error "too many open file"
when benchmark testing, spoa_example have this error too, even enable the
async and pipelining.
But haproxy 1.8 have no this kind error.
Thanks for any help.
Best regards