Fix storage warnings on MySQL 5.7
Fix storage warnings on MySQL 5.7

This is a port of
https://github.com/symphonycms/symphony-2/commit/5e3bf4f91ecddc80260d584634040b9e733f921d#diff-19f01796e1be3eb30628a9acd35514d5L204

cc @brendo

Picked from 9363d504ee

symphonycms/symphony-2,symphonycms/symphony-2,jensscherbl/symphony,jensscherbl/symphony,michael-e/symphony-2,bauhouse/sym-todo-list,bauhouse/sym-todo-list,michael-e/symphony-2