Fix line break handling in Cloudflare template

Fix line break handling in Cloudflare template

Cloudflare's IP list has gone back and forth between including a trailing line break and omitting it.

When a trailing line break was first added in 2015, it resulted in a bug: https://meta.discourse.org/t/issue-with-cloudflare-template/35113

The trailing line break was removed again in 2021: https://meta.discourse.org/t/cloudflare-template-broken-again/200219

This fixes the template so that it will work regardless of extra line breaks.  It will also safely ignore any empty lines that may appear in the files.