Renamed packages are flagged immediately

[smoelius]

Suppose a package X is renamed as Y. Then package X will be flagged immediately with "X (not in <repo>)". This is a false positive.

You can see this right now with the icu_locid package:

$ cargo unmaintained -p icu_locid
Scanning 1 packages and their dependencies (pass --verbose for more information)
1/1 (100%)        
icu_locid (not in https://github.com/unicode-org/icu4x)

The package was renamed recently: https://github.com/unicode-org/icu4x/blob/83441614dd3b7ce628031926c279fb25c97f7461/CHANGELOG.md?plain=1#L21-L22

I not yet sure how best to fix this.