ncd/extra/address_utils.h: add NCDVal_HasOnlyContinuousStrings() assertions
ncd/extra/address_utils.h: add NCDVal_HasOnlyContinuousStrings() assertions

Ernillew/badvpn,Ernillew/badvpn,Ernillew/badvpn,Ernillew/badvpn,Ernillew/badvpn