This reverts commit 69b6fe0d.

It broke horribly as expected :-) Trick is that if package is not found, the
dependency is mallformed anyway, so it is better to just get rid of it and hope
for the best than to break with weird error. Correct solution would be exiting
with the correct error but first of all make dependencies accross feeds work.

package-metadata.pl is currently not generating dependency if there is
no such package. This just hacks that away and generates that dependency
all the time. This might break horribly.