The private commit email is automatically generated in the format:
id-username@noreply.HOSTNAME

GitLab instance admins are able to change the HOSTNAME portion,
that defaults to Gitlab's hostname, to whatever they prefer.

Remove PersonalAccessTokensFinder#find_by method

See merge request gitlab-org/gitlab-ce!22617

find_by_token is overriden by TokenAuthenticatable which can be easily
missed or confused with #find_by(:token) defined by ActiveRecord. First
step for safer usage is to remove #find_by.

This moves the `where` in the `has_many :keys` association in Project to
the Key model. This allows EE to override this method, instead of
modifying the source code directly.

This moves the `1.hour` constant used as the LDAP sync time to a
separate method. This allows EE to override this method using a module,
instead of directly modifying the source code.

[11.4] Fix Token lookup for Git over HTTP and registry authentication

See merge request gitlab/gitlabhq!2577