log:
 libnetlink: RTNETLINK answers: Invalid argument
 ppp0: f7bb00a79ef667d2: failed to set IPv4 address: Invalid argument

ipaddr_add_peer() called only with mask equeal 0 or 32, but w/o
zero-allocated structs it contans garbage in some cases.
so, instead ipaddr_add() was called with wrong mask value.
also, init chap-secrets mask for the same reason.