Since ERP5 commit d4eda7ea49 (CMFActivity: show InnoDB history list
length in console watcher, 2020-09-15), the wrapper script no longer work
because accessing history list length require PROCESS privileges.

In the case of ERP5, mariadb database is dedicated for ERP5, so we can
grant the PROCESS privilege also to erp5 default user, which is used in
the wrapper script.

We don't grant the permission to test users because they don't need it.