ABillS + FreeRADIUS + Accel-PPP only issue one DNS

Once after installation ABillS + FreeRADIUS2 + Accel-PPP (ipoe) noticed that for DHCP clients receive only one DNS server.
Access-Accept from FreeRADIUS was this:

Sending Access-Accept of id 1 to 127.0.0.1 port 57481
        Session-Timeout = 604800
        PPPD-Downstream-Speed-Limit = 51200
        Framed-IP-Netmask += 255.255.255.0
        Framed-IP-Netmask += 255.255.255.0
        Acct-Interim-Interval = 600
        DHCP-Domain-Name-Server += 8.8.8.8
        DHCP-Domain-Name-Server += 8.8.4.4
        PPPD-Upstream-Speed-Limit = 51200
        Framed-IP-Address = 172.20.20.20
Finished request 40.

Users received only the second DNS (8.8.4.4), in ABillS, in the “Setup>Access Server>IP POOLs” two DNS – 8.8.8.8.8.8.4.4 were specified.

Since the developer of ABillS did not know the reason, I set the DNS in /etc/accel-ppp.conf configuration:

[dns]
dns1=8.8.8.8
dns2=8.8.4.4

And since the DNS from Access-Accept from FreeRADIUS has more priority than those in the Accel-PPP configuration, I removed them from all IP POOLs SQL by querying:

update ippools SET dns='';

If that their-you can specify in all IP POOLs like this:

update ippools SET dns='8.8.8.8,8.8.4.4';

After that, the Access-Accept from FreeRADIUS did not pass DNS:

DHCP-Domain-Name-Server += 0.0.0.0
DHCP-Domain-Name-Server += 0.0.0.0

And Accel-PPP started issuing those that are specified in its configuration.

I note that when DNS was issued from IP POOLs billing, then in the Accel-PPP logs with DHCPv4 Ack they were displayed as:

<DNS 8.8.8.8> <DNS 8.8.4.4>

And when they started to be issued those that are specified in the Accel-PPP configuration, then:

<DNS 8.8.8.8,8.8.4.4>

UPD: In new versions of Accel-ppp, this problem is solved, you can transfer several DNS even though it is so.