archiver.bbclass: check if package contains a copyleft license
The copyleft filter is only excluding packages that contain a
closed source license. This is because oe.license.is_included()
returns a boolean value that indicates if the license is excluded,
and a string that contains the matched included licenses. If the
string is empty it indicates that no licenses were matched.
Reject packages that do not contain a copyleft license.
[YOCTO 4630]
Signed-off-by: Kevin Strasser <kevin.strasser@linux.intel.com> Signed-off-by: Saul Wold <sgw@linux.intel.com>