add a hack to get the current date from either sqlite or psql
add a hack to get the current date from either sqlite or psql

This is used to test with sqlite and use postgres in production
environments

Signed-off-by: Jan Losinski <577c4104c61edf9f052c616c0c23e67bef4a9955@wh2.tu-dresden.de>

agdsn/pycroft,agdsn/pycroft,lukasjuhrich/pycroft,agdsn/pycroft,agdsn/pycroft,lukasjuhrich/pycroft,agdsn/pycroft,lukasjuhrich/pycroft,lukasjuhrich/pycroft