/usr/share/udhcpc/default.script works wrong with 2 dhcp interfaces

I've just installed Alpine 3.12 as vbox guest system. I've configured 2 network interfaces:

1. nat (dhcp)
2. host-only interface (dhcp)

Nat dhcp server gives correct nameserver. Everything is good when only nat inerface is enabled. But when there is another dhcp interface without nameserver, /etc/resolv.conf is cleaned depending on which interface is being processed.

I think it is possible to append interface nameserver string to /etc/resolv.conf without cleaning it.