The user of this find module has to do it, so that they can specify the
purpose of using canberra in their application. We can't do it twice,
it leads to
- Warning: Property DESCRIPTION for package Canberra already set to "Event sound library", overriding it with "Library for generating event sounds"
The documentation for FeatureSummary always does find_package
and then set_package_properties, i.e. it was never meant for the
finder to do this.