PersistentStorage::RestoreDefaults causes crashes

[stephenhensley]

I think this is vestigial from a previous version of the class that worked on a reference to the initial struct passed in to initialization.

Pretty sure this can be resolved just by changing

*settings = default_settings;

to

settings = default_settings;

However, I'm not 100% sure if the default copy operator will work or not. So we should test it.