Forbid blocking IP ranges as big as /1 and /2, as done on ruwikiquote using the API

PKSA-2rqt-w99v-qcks CVE-2019-12472

Affected package: mediawiki/core

Affected version: >=1.27.0,<1.27.6|>=1.30.0,<1.30.2|>=1.31.0,<1.31.2|>=1.32.0,<1.32.2

Reported by:
FriendsOfPHP/security-advisories