rc.initial.setlanip fix validation of CIDR within range

Currently this allows the user to input any number for the CIDR. I happened to try 44 for an IPv4 CIDR when playing.
This fixes that little bug - I think it is good to commit that first/separately so it can be identified apart from the other (y/n) checking/handling I am working on. Better to have separate commits for distinct bugs.
Merge pull request #1383 from phil-davis/patch-10
Update service providers xml to sync with upstream