alchemy/zippy, Member::getLatsModifiedDate() return DateTime, not string

[rotdrop]

Hi there,

I think I stumbled over a bug here:

https://github.com/wapmorgan/UnifiedArchive/blob/5f02ad060223fd714aaf7f64a18d8e819ac0ab93/src/Drivers/AlchemyZippy.php#L232-L233

At least in version 1.0 (the current since 2021) Member::getLastModifiedData() returns DateTime, not a textual representation of the last mtime. Hence strtotime() -- which expects a string -- fails. According to "git blame" this has always be the case(?) which surprises. I'll shortly submit a pull request.

Best

Claus