Bug in vauth_getall in vmysql.c (vpopmail 4.9,4.9.5)

[Svyatoslav Trukhanov]

Hello.
I use vpopmail 4.9+MySQL.
If I try to call 
vauth_getall(dom, 1, 1);
vauth_getall(dom, 1, 1);
when second function call I have message "vsql_getpw: failed select"
First I see this bug in qmailadmin, when try to use index or find user.
I think that sql result not cleaning in this case.
This is present in 4.9.5 too.

I patch 4.9 (patch in attach) and it work properly.

vmysql.diff