Fix bug that made pkg repo segfault
Fix bug that made pkg repo segfault

Introduced in 5dc36026fc60c64763d82a69ef2921b3cd78e913, pkg repo -l
crashed on packages (meta ports) that don't install files on their own.

khorben/pkg,junovitch/pkg,en90/pkg,Open343/pkg,junovitch/pkg,skoef/pkg,Open343/pkg,en90/pkg,khorben/pkg,khorben/pkg,skoef/pkg