[ticket/12074] Managing extensions doesn't produce any log entry

PHPBB3-12074
[ticket/12074] Don't log errors

PHPBB3-12074
[ticket/12074] Update the visibility of the constructor

PHPBB3-12074
Merge pull request #2429 from Nicofuma/ticket/12074

[ticket/12074] Managing extensions doesn't produce any log entry

* Nicofuma/ticket/12074:
  [ticket/12074] Update the visibility of the constructor
  [ticket/12074] Don't log errors
  [ticket/12074] Managing extensions doesn't produce any log entry