! Improve handling of login history (fixes #2290)

This does three things:
1. Hides the option to view login history in the profile if the setting is disabled.
2. Sets it to a default of 30 days to be consistent with the help text
3. Adds the standard "(0 to disable)" help subtext for the setting in the admin center (should be obvious, but can't hurt either way)

Signed-off-by: Michael Eshom <oldiesmann@oldiesmann.us>