merge with 3.21.3
The change in unittest_serverctl.py is needed because of daef7ce08fea
(from 3.20.11) and 3914388b2d0f (from the 3.22 branch). Due to both
changes, CubicWebTC.config.repository no longer creates a new repository
(and thus, a new connection). Since both DBDumpCommand and
CubicWebTC.tearDown try to shutdown the repo, tearDown breaks apart.
The solution is to temporarily disable ServerConfiguration's config
cache. By forcing DBDumpCommand to get a new configuration object, it
then gets its own Repo object, allowing tearDown and DBDumpCommand to
work independently.
change_attribute_type('CWCache', 'timestamp', 'TZDatetime')
change_attribute_type('CWUser', 'last_login_time', 'TZDatetime')
change_attribute_type('CWSource', 'latest_retrieval', 'TZDatetime')
drop_attribute('CWSource', 'synchronizing')
add_attribute('CWSource', 'in_synchronization')