gtld_map: capture `.active` removal. (#255)
gtld_map: capture `.active` removal. (#255)

IANA has revoked the `.active` gTLD as of 2019-02-17.

```
$ curl https://www.icann.org/resources/registries/gtlds/v2/gtlds.json 2>/dev/null | \
  jq '.gTLDs | .[] | select(.gTLD=="active") | .removalDate'

"2019-02-17"
```
zmap/zlint,zmap/zlint