[pkg] Add missing entries to MANIFEST.in
Detected by running `check-manifest
<https://github.com/mgedmin/check-manifest>`_. Add a tox environment
accordingly.
Closes #15229018.
option_group_changed('port', 'main', 'web')
option_group_changed('query-log-file', 'main', 'web')
option_group_changed('profile', 'main', 'web')
option_group_changed('max-post-length', 'main', 'web')