dns/dnsmasq-devel: update to v2.91test1

ChangeLog: https://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=blob;f=CHANGELOG;h=8982a93cb95c074e652a19b6f2a6a33dfffba04a;hb=5d32f35bdcd6105acc206e0afd0516dee2dd1439

Note the test I've added has not seen serious testing, it's just
to fix compiles, and might impair how we enumerate interfaces.

I've sent it upstream to the dnsmasq-discuss@ mailing list so Simon or

other people are aware and can provide a different fix.

This is a TEST release, treat it as such.