pkg-config file does not use Libs/Libs.private correctly

[mia-0]

The Libs: line should only contain the shared libraries required to use libzip (i.e. just libzip itself). Libs.private should contain libraries required for static linking, i.e. the dependencies.

In particular, -lbz2 should be under Libs.private and not under Libs – otherwise, it breaks linking in many cases.

[dillof]

Thanks, merged.