Revert "Do not report birthdate anymore"

This reverts commit d245cdaf7ff32113b4f61ff8c6b1a4121aaf805d.
Keep _age logic but only send 0s

Signed-off-by: Martin Abente Lahaye <tch@sugarlabs.org>
Release 0.4.2-2

Bugfix release

Signed-off-by: Martin Abente Lahaye <tch@sugarlabs.org>