License files not correctly found for `sct` package

[jwodder]

Currently (as of its v0.7.1), the source for the sct package (a dependency of rustls) contains the following license files:

• LICENSE — lists the licenses that sct is distributed under and refers the reader to the other files
• LICENSE-APACHE
• LICENSE-ISC
• LICENSE-MIT

However, cargo-lichking only bundles the LICENSE file, which is not a proper license file, and it ignores the actual license files right next to it.